A few updates

I'm not doing very well with regular blog posts this year, so here's a bit of a catch up on some things I've left hanging.

Solar panels
The big project. When I last wrote about these, I was waiting for sunshine to see how they'd do.

Well, they work, but they don't put a huge amount of heat into the tank. I found this very demoralising at first, but Ian pointed out that it takes quite a few hours to put a significant amount of heat into that tank with fire, so I should feel too bad about modest performance from a couple of old radiators. There are one or two more things I could do that might improve performance. In the meantime, we've had warm-ish water out of the taps this summer, instead of cold, in spite of weather that barely qualifies for the name, summer.

Shower
It turned out that we really do want a different temperature in the kitchen than the shower, so we were forever turning the valve up or down, and trying to remember where we'd left it. Also, the temperature at the shower head wasn't entirely determined by the valve in the cupboard across the hallway; whether or not the underfloor heating was on made quite a big difference to how much heat was lost between the two. Added to that, the valve started to get sticky. I think maybe these valves shouldn't be treated this way. We needed an upgrade. One new thermostatic mixer valve was purchased, plus a connector or two, and plumbed in.

We now have one temperature for the shower and a slightly higher temperature for the hot taps. Perfect.

Wine yeast
At about three months old, the blackberry wine made with bread yeast was still pretty sweet, but pleasant and quite drinkable. That made with wine yeast, in contrast, was horrible. It was really rough, exactly like every home-brewed gutrot you've ever tipped into a potted plant when your enthusiastic home-brewing friend isn't looking.

Well, they look pretty similar

Now, at one year old, the bread yeast wine is no longer sweet at all, though still quite fizzy (correctable with a vacuum pump), and has quite a decent flavour. The wine yeast wine is surprisingly a little sweeter. It has mellowed and completely lost the rough edge, and has a more complex flavour than the bread yeast wine. In conclusion, then, both are fine for older wines, though wine yeast is better, but bread yeast is far superior for a very young wine, if you're happy to drink it fairly sweet. Before you decide that bread yeast is all you need, though, I also used it for my other wines. The dandelion wine was very good, but the oak leaf, beech leaf, and blackcurrant wines are still fermenting now, and still very sweet. It seems that bread yeast doesn't stand up well to tannin.

Vinegar
My too-sweet beech leaf wine remains resolutely sweet. I chuck in a bit of yeast or some more vinegar from time to time, but nothing doing. I think I may have discovered the solution to the antibiotic time-bomb, as this stuff kills everything I throw at it. It's a new multi-purpose sterilising solution.

Pickled mushrooms
These are very nice.

Perhaps a little stronger on the vinegar than I'd ideally like, but that has to be good for storage. It feels odd to be eating preserved mushrooms right in the middle of mushroom season, but I had to try a few, and yep, they're good.

Willow bench
Is mostly still alive. Many of the thinnest pieces died, but most of the thicker, more structural pieces have survived, and are putting out thin shoots of their own to replace the ones that died.

It's still not strong enough to sit on, but I'm sure it will be in time.

Crocosmia
In our first February here, when I was carrying out a serious assault on the garden to get it ready for my first year of planting, I moved some crocosmia from a flower bed to a steep bit of hillside. It was hard work. While not yet the dazzling display of colour that I have seen from these plants, they're getting established nicely and give a good show of orange flowers scattered across the hillside.

A smattering of crocosmia

In the background you just about be able to see the willow fence alongside the terrace. That's doing quite well, with almost no losses, and may yet provide valuable support if the terrace does start to break down.

Nearly there!

Since I last posted, I've made more progress on the solar panel project (which is just as well, as I'm not doing anything else!) One job that I had thought might be beyond me was fitting a new electric socket into the cupboard where the pump is. I've never tackled mains electricity before, and didn't really know where to start. However, browsing through the Readers Digest DIY manual (as you do), I found nice clear instructions for taking a spur from one socket to supply another. That's exactly what I needed - I could use the socket across the hall that we'd been plugging the extension lead into. Far better to have the wire running under the floor than over it. All I had to do was lift the floor...

In one way, that wasn't too bad as I'd laid that bit of floor myself, so knew where I was with it. On the other hand, the pipes set into the floor had been connected up since then. At least they were flexible plastic, so should cope with having the board gently eased up. I did just that and, after a slight setback when I discovered that the wires to the socket went up, not down (so no hole in the floor beneath them), the job went entirely to plan, and I now have a new double socket in the cupboard. I also tidied up the wiring in there and added a switch for the pump. First I had to find a switch, which came to light when I took the coats off the coat rack before soldering just above them. There was a thermostat on the wall, no longer in use (obviously). That must have a switch in it! I thought. I took it to pieces and discovered not only a switch that's normally on, push button for off, but also a wiring diagram. Perfect. This enables the pump to be switched off with the solenoid valve left open, which is necessary for draining the system. In addition to a switch, the pump now has a connected earth wire. Yes, I know.

Believe it or not, this is the after tidying photo.

I've connected up all the plumbing. This included a few solder joints, most of which were done twice, though in my defense, I was dodging hail showers at the time, and re-doing the leaky connector over the coat rack that I hadn't quite fixed last time I tried. I'd expected the compression joints to be relatively easy, but even they threw up a few challenges. One pipe running down the side of a radiator wouldn't go past the plug I'd put in the other corner, but luckily I had a flatter one in a different corner, so could swap them around. In spite of writing Make sure 1st and 2nd boxes are close enough together for flexi-hose on my list, they weren't, but I solved that by bending the solid pipe instead of cutting it to only just longer than the box. When I went to raid the old radiators for bleed valves, I found that most of them had the grub screws missing. I don't know how that happened - I don't remember taking them out. I used a cap in place of one bleed valve - it works almost as well. Finally, I nearly destroyed two nuts trying to tighten a joint that I'd failed to put an olive in. Luckily, I checked.

Having made all the connections, I needed to fill the system to check for leaks. That meant going up into the loft, which meant a ladder that I discovered, on first climbing it, wasn't very firm on the floor. That is, the floor is dusty and the ladder slipped. I caught it before it went too far, but came down quickly and resolved not to go up again without someone to hold the bottom. Ian being out at work, I called on a neighbour, who kindly came round and held the ladder for me, and was quite interested to see the rest of the system too. Much to my surprise, not to say delight, there were no leaks. Not one.

The next step was to replace the plain water in the system with an antifreeze* mix. I'd originally thought of mixing it up in a watering can then pouring it into the header tank in the loft. Unfortunately there wasn't enough headroom above the tank for that plan to work. When Ian got home from work I asked for his input on the problem. He thought a bit then said, I do have that 12 volt pump and hose that I used to use for biodiesel. Maybe we could pump it up there. I have a spare battery, too. While he went off to fetch those things, I continued to search for inspiration on the internet. Surely other people have solved this problem? Well yes, but most of them solved it at the design stage, incorporating charging valves into the system for this very purpose. Then I came across the following very useful advice:

you could try this "cheapskate" approach:

Make no connection whatsoever to the water main. Use a 5L house-plant sprayer (Hozelock). Remove spray head, fill container with antifreeze water mix, attach hose to system drain and pump. The pump will easily deliver up to 3 bar.

I wasn't sure whether our pump could deliver that kind of pressure, but filling through the drain would be a lot easier than getting the pump within reach of the header tank. It had to be worth a go.

Pump in a bucket of bright pink antifreeze, powered by car battery and battery booster

It worked, just about. We ran the system pump to help it, and there was lots of running out to open bleed valves, then close them again in case the antifreeze all escaped as well as opening and closing the drain to take liquid in, then not let it out again. This required a lot of coordination between the two of us. The pump didn't quite manage the last litre and a half, so Ian took that up to the loft in a jug, and I think we may need to top up with a bit more water, as there are distinct gurgling sounds when the pump's running. However, we now have all the panels connected up and full of antifreeze, ready to go. The controller is doing its thing, and reporting slightly more information than it was last time I wrote about it.

Controller display, now fixed to the shelf

In addition to sensors in the panel and in the tank, I now have one on the pipe just before it goes into the tank. Ideally, this should be at about the same temperature as the panel when the pump's running, but as you can see, it's considerably lower. That means we've lost almost 20°C between the panel and the tank. Not good. Insulation is needed.

I started insulating the pipes around the panels, but I need to improve on this. I'll do more when the weather's better.

More shiny wrapping will be added

For the next stage of their journey the pipes cross the conservatory. I had an idea that since they're running under a transparent roof, maybe they could absorb some more sunlight on the way. It's probably a daft idea, but I persevered. Using an offcut of the roof itself, I made thee sides of a box.

Bent polycarbonate roofing

It is possible to bend polycarbonate cold, but only if you can take it a lot further than the angle you need, to allow for spring back. I couldn't do that, so had to apply heat. This meant waving a blowtorch at a piece of plastic I was holding in my hand. I managed not to burn myself, which is quite remarkable considering how often I burn myself on the oven. The other day I even managed to burn my finger on one of the solar panels. Yes, it did get that hot!

To go inside the box, I taped up some of the thin insulation for behind radiators and pleated a few layers between the pipes, and some more around them. Just the top was left open to the sunshine. When I say open, I mean covered by twin-wall polycarbonate roofing.

Boxed-in pipes

I'm not entirely convinced by this, but it has to be better than it was. If nothing else, it's a lot tidier.

Items remaining on my list are: Insulate pipes and touch up paint on window frames, both of which are waiting for better weather, screw down window on first box, which I'll do when I'm quite sure the system doesn't need bleeding any more, fix blinds to boxes, which can wait, as it's only needed if we go away in the summer, and possibly not even then, figure out clock for controller and program data logging, the first of which I spent quite a lot of time on today, and one I added yesterday, calibrate sensors. When I checked first thing, the display reported that the panel was at -2°C but there was no sign of frost, so it's evidently not accurate. I had meant to do this before I taped the sensor to the back of a solar panel, but I forgot.

As for figuring out a clock, this is so I can record temperatures and keep track of when they occur. People usually use an external, battery powered clock for this, but it is possible to make the Aruduino keep track of time and date after taking a time signal from a PC to start it off. I spent a long time looking up how to do this (it's here, if you're interested), then this afternoon our electricity kept flicking on and off, reminding me why the external clock's a good idea. I guess I'll be getting one of those then. That means more soldering. Hmph.

So there we are, nearly finished. The only remaining job that's going to make a difference to the effectiveness of the panels is adding insulation, and I'm well on the way with that. All I need now is some sunshine.

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* I spent far too long considering what kind of antifreeze to use. Our system has the unusual feature of two walls of copper between the solar loop and the drinking water. This means I'm not constrained to use non-toxic antifreeze (if you have only one wall of copper separating them, you should use propylene glycol, which is food safe, in case there's a leak. Otherwise you might end up poisoning your drinking water), so could consider other alternatives. Methanol has a low freezing point, low viscosity, and an even higher specific heat capacity than water. It would be absolutely ideal if it weren't for - and I found this fact very frustrating - its tendency to evaporate, filling the space with poisonous, explosive gas. I settled for car antifreeze in the end, which is pretty much where I started from.

The third panel

I'm still working on the solar panels. They're not finished yet, but I'm making progress. This post is a bit about the design of the system.

As soon as you add a second panel to the system, there's a decision to be made about whether to connect them up in series (water goes through each panel in turn) or in parallel (there's a junction to split the water so it goes through both/all at once, then another junction to bring it back together again). Guidelines that I consulted on how to connect up solar panels tended to describe a combination layout, e.g. four panels arranged in two parallel runs, without discussing the pros and cons of each option. I had to do some general reading, and some thinking for myself, and here's what I came up with.

Panels in series make a longer loop for the water to go round, which means a more powerful pump is required. Panels in parallel require balancing to make sure one of the panels doesn't end up dominating the system, which the water essentially bypassing the others. I think that plumbers tend to favour parallel systems for these reasons, as balancing systems is something they do all the time, so it's no big deal to them. As for the effectiveness of catching heat from the sun, given a certain amount of sunlight falling on a given surface area, it might seem that there's no way that varying the plumbing could affect how much heat is captured, but there are a few factors that are worth considering.

Specific to my system is the fact that radiators have a high volume of water relative to commercial flat panel solar collectors. This means that they aren't so responsive; they take longer to heat up, so if there's only a short period of sunshine, they may not get hot enough to trigger the pump and take the heat into the thermal store. Hot enough is an important point here: If my store is at 50°C already, the incoming water needs to be pretty hot before it's any use. This means I want to maximize temperature, if possible.

On the other hand, there's the question of panel efficiency. For all the insulation I've put in, they will radiate heat back into the air, especially through the glass. If heat can be taken away from the panel when it's only a little above air temperature, then very little heat will be lost to the air, so the panel will be operating at a higher efficiency than it would if it was a getting a lot hotter before the heat was taken away and stored. Now we have arguments in favour of both high and low temperatures.

Let's look at how serial and parallel systems vary in terms of temperature. In a parallel system, water in all of the panels heats up at the same time, starting cool then, if it gets hot enough, all being pumped into the store at once. In a serial system, water goes through each panel in turn, so the first panel might be considered a preheat panel, and the last a topping up panel. This means there are different temperatures at different points in the system, which could be a good thing, considering the conflicting requirements mentioned above. The first panel can operate at a lower temperature, and so be more efficient, and the second panel brings the water up to a temperature high enough to be useful, i.e. hotter than the water already in the store.

However, there is a slight weakness in the description I just gave you. Water goes through means that the water is already flowing round the system. This won't happen until the last panel gets hotter than the stored water which, radiators being slow to respond, could take quite some time first thing in the morning. This brings us to the third panel.

How about having a booster panel that will heat up quickly and get the water flowing round the system? There are many designs for DIY solar panels to be found on the internet, and most of them involve much smaller volumes of water than the radiator design. If I made a small one of these and added it after the bigger panels in the series, it would heat up more quickly when the sun hits the panels in the morning and so start the water circulating before the other panels had got up to temperature. After that, it should serve to boost the temperature as the preheated water flows through it, so giving the higher temperatures needed to be worth adding to the store, at the same time as allowing the other panels to operate at cooler, more efficient temperatures. That's the theory, anyway.

I had plenty of microbore (10mm dia) copper pipe salvaged from the old central heating, and a sheet of aluminium that was originally behind a gas fire, and has more recently been part of my heated propagator. These could be used to make a solar collector along the same lines as this one described on builditsolar.com. I went for serpentine design to save making a lot of connections - I don't need a high volume of water here, so it doesn't matter if the pipes are widely spaced.

Having bent my pipe, I then used a 10mm steel bar - I have no idea where that came from - and hit it repeatedly into the aluminium sheet to make grooves. If you're thinking of trying this, it really is worth making a jig to shape the grooves. I started by setting the workbench to the appropriate width, but it kept opening out, which absorbed much of the energy I was putting in with the hammer.

The grooves in this aluminium sheet are carefully aligned to the bent pipe (visible in the background), not accidentally wonky

Once I had the two parts made, they needed connecting together. Following advice from builditsolar, I used silicone gloop to fill the gap between aluminium sheet and copper pipe. I then drilled some holes and tied the pipes into place with cable ties.

Each cable tie is looped twice over the pipe and joined at the back. I had hoped to pull the aluminium more tightly around the pipes, but the cable ties weren't strong enough.

All this got me as far as selecting a radiator for the other panels. I then selected a suitable sized window and made a box in the same way as I had for the other panels (I didn't tell you about the second panel. It was very much like the first one, except that the best fitting windows were wood framed house windows, which took a lot more work to prepare, being old and somewhat rotten). At some point before putting the insulation in, I realised that it would be a good idea to solder the connections that needed it before the pipes were snuggled up next to plastic insulating stuff. I'm glad I realised at that point.

Here is my finished booster panel, out on the hillside. The diagonal lines are reflections of overhead cables.

As you see, the window wasn't a very good fit for the collector, but it does allow space for a bleed valve to one side. The vertical pipe disappears under the top layer of insulation, to exit the box at the bottom.

And here it is in context:

Three solar panels, all fixed to their brick bases.

So, I now have all three panels in position. Once I've connected them together I'll be able to fill them and start catching sunlight. That isn't quite the end of the project, though. Insulation is quite important, too, and it would be nice if the power supply didn't run across the hallway to reach the pump.

One solar panel (box) now in position

When I checked my brick bases yesterday morning, they were had indeed set firm and were still horizontal and vertical in the correct places. This was pleasing, if not very surprising. At this stage, I was able to make the final measurement of how steep the bank is, or more precisely, the slope between the two bases. Getting a panel set up at the desired angle to the sun isn't straightforward when you're standing it on such an irregular surface. However, having given it much thought, I had a plan, and measuring the slope was the first step.

Tools for measuring orientation

As previously mentioned, the compass proved less useful than anticipated (and wasn't needed for this stage of the job, in any case), and it turns out that a paperclip makes a poor plumb bob, but the spirit level and protractor, held against a floorboard resting across the brick bases, were quite effective. Once I'd measured the angle of the bank, and I knew (from calculations) the desired angle towards the sky, I could prop up the solar panel box indoors at the right attitude.

Solar panel box propped up on bits of firewood

It's not the most stable of arrangements, perhaps, but it did the job. With this in position, I took the spirit level and drew horizontal lines around all the legs. This part was more difficult than I expected, but I ended up with this:

One solar panel leg marked out for cutting

Do you see where I'm going with this yet? If I cut the legs to horizontal, and have brick bases that are also horizontal, the two should fit together to give me the right angle of the panel. Added to this, I need a vertical hole in each leg for the peg. That is, it will be vertical when it's all in position, but at time of drilling, it has to be perpendicular to the cut surface of the leg. These holes also need to be exactly the right distance apart, so I measured the pegs again, for the umpteenth time. I used a gimlet to make pilot holes as it's much easier with a hand tool to give it half a turn or two then check again with a set square to make sure it's still going in the right direction.

Having drilled the holes, I couldn't resist taking the box up to the bank to see whether it fitted. Halfway up the steps I thought, I'm not going to want to do this again. Luckily, it fitted!

Solar panel box, standing on front bases only

Not only did it fit perfectly, but it stood up on its own, too. That was better than I expected but I thought I'd better stick to the plan and add the back legs. After all, it will be carrying a lot more weight when it's finished. Having got the box in position, the next step was to find the positions for the back legs, which I did with a plumb line made by tying a brass nut to a piece of string and hanging it under the legs. I then mortared bricks and pegs into position, again aiming for horizontal bricks and vertical pegs, though it was slightly less critical this time.

Once the mortar had set (I left it over night, with the panel propped up for extra support, though it didn't really need it), it was time to fill in the gaps. There were some bits of wood up there that I'd taken up some time ago when first thinking about how to support solar panels. I think they were from the leylandii hedge. In any case, they looked quite suitable for making back legs from. I measured these against the gaps between panel feet and brick bases, cut them to length, drilled holes, somehow eased them into the gap, and finally added brackets to connect them up at the top.

First panel box fixed in position

After that, I applied copious quantities of creosote then brought the glass cover out to go on top, which I finished just as the first few drops of rain fell. Now I can turn my attention to the second panel.

Solar panel update

Since finishing the new terrace, the solar panel project has been top of my list of priorities. I've already had one panel connected up and working, complete with pipework, pump and automatic controller, and since then I've more-or-less made a second panel, and made a start on the third, so it felt like I was fairly near the end of the job. I hoped to get it finished by the end of February.

Unsurprisingly, that didn't happen. Feeling somewhat despondent, I sat down and wrote a list of all the tasks that needed doing before I could say the job was finished. The list ended up looking like this:

There seem to be quite a lot of jobs still to do. I managed to cross a few off by the time I took this photo.

That didn't improve my state of mind greatly; it was considerably daunting. Still, at least it was now obvious why I hadn't finished it all in the expected timescale. I started tackling items on the list and felt quite productive on some days, but on other days I got hardly anything done. I started to sense a reluctance in myself. This came into sharp focus when another, really quite unpleasant, job presented itself, and I jumped to do it. Hmm, this isn't just laziness... I'm clearly avoiding the solar panel project.

What's my problem, then? I think that as the day of reckoning comes into sight - not just a test to see if it works, but a Tada! Finished! moment - I'm getting anxious about messing it all up. This kind of thing is probably stating the bleeding obvious to many people, but I'm not very good at being in touch with my emotions, so I have to resort to detective work to figure out what's going on in my head.

I realised that I've also been making things more difficult than they need to be in the name of efficiency. It really doesn't matter if I have to clean creosote off the paint brush several times. It doesn't matter if I have to make up several batches of mortar, even if that means wasting a bit. This was compounded by the way I wrote the list, with a couple of sets of jobs marked x3, lumping them all together into one. If I take away the restriction of doing certain jobs for all three panels at once, then I can focus on one panel at a time, which is less overwhelming. It also means I can get the first one up on the bank, out of the way, so I have more space to work on the next one.

Having given myself a good talking to this morning (with help from a sympathetic husband), I tackled one of the scarier jobs. I'd decided to make brick bases to stand the panels on, which required a bit of bricklaying. The only bricklaying I'd done before was the arch over the fireplace (not actually mortared in at the time I wrote that post - I did it more recently), which I wasn't very pleased with, so I doubted my ability to do the job successfully. The bases I had planned were pretty small, just four bricks each, two on two, but I think that might be even more difficult than a good long stretch in which each brick supports the ones on either side.

There were several other factors that added to the difficulty. I wanted a peg to stick up out of the centre of each base so that I could drill a hole in each leg of the panels and fit them on. (One job that I've crossed off the list was investigate tent pegs. I did, and found some old bent pegs that I'd failed to throw out, and they seem suitable.) To fit nicely, the peg would need to be vertical, the bricks would have to be horizontal, and the distance between the pegs needed to be fairly precise. It's no wonder I was wary of this job.

I'd done some measuring out, and cleared some turf to make space for the bases on the bank, so I had my bricks placed in position:

The floorboards were for measuring the slope of the bank. Fixing down the conservatory roof properly is below solar panels on the to-do list.

Having dithered about over whether to get ready mixed mortar or sand, cement and lime separately, I'd bought the latter after bumping into a friend in town who said he could use the rest of it (it's much cheaper to buy the components separately, but isn't available in small quantities). I double checked the measurements again, lined up various tools (spirit level, set square, tape measure), and mixed some mortar. I added far too much lime by mistake, so added some more of the other two, then found I had too much stuff to mix in my little bucket, so turned some of it out onto a school bus sign that was sitting around, before adding water and mixing. I was finally ready to start fixing my bricks in place.

It certainly wasn't easy, especially as I needed to be so precise with the positioning, but I think I did a reasonable job.

One brick base mortared in, complete with tent peg.

Two of the bases went onto the concrete wall-top at the edge of the conservatory. I'd deliberately shortened the conservatory roof to allow for this and I'm glad I did, as it's a bit tight for space here. However, most of the tent pegs were a bit long for use here. Where the bricks were on the ground I could bury one end of the peg into the earth (if I moved the stones out of the way) but not here. Luckily, I had two shorter pegs that I could use, so I did.

Commenting on the tight space there reminds me that I haven't told you about determining the position of the panels, which was a job in itself. I won't go into great detail, but I used the equation from this web page entered into a spreadsheet with solar radiation data from the same source, plus some zeros for times of day when the panels would be in shade. I then tweaked the figures for north-south orientation (or more relevantly, south vs. east) and tilt of panel until I found the maximum radiation captured. The results were 15° east of south and 53° from horizontal, which is our latitude. It was quite nice to see that come out of the calculations; it gave me some confidence that they were correct.

It's all very well knowing what tilt I'm aiming for, but implementing that on a sloping bank is another question entirely. I've mentioned a couple of features of my plan to meet this challenge - horizontal brick bases and floorboard measurement of the slope of the bank - but I'll come back to the rest of that in another post. Orienting the panels 15° east of south should have been fairly straightforward. All I needed was a compass, or so I thought. It turned out that some feature of this bit of hillside interfered with the compass. I could get a plausible reading for north-south at about four feet above ground level, but as I lowered the compass, the needle turned round until it was pointing more than 90° in a different direction. I dread to think what's buried there. (Actually, I was more than tempted to dig... but resisted.) Eventually, I decided that the fence was running pretty much north-south, so worked from that.

So far, I have three and a half brick bases mortared in place. I finished my batch of mortar after fixing the first layer of bricks of the fourth base. That's OK, though, because I'm concentrating on one panel at the moment, and setting the front two feet in place first before propping it up to determine where the back two bases need to go. Hopefully, when I check again tomorrow, the bases will be firm, still horizontal, and the pegs will still be vertical and the correct distance apart.

New shower

We have an old electric shower here. It's very feeble, but in summer it does provide our only source of running hot water; for anything else we have to boil the kettle. The long term plan has always been to replace it with one plumbed into the hot water system, but that rather depends on having a fully functioning hot water system, which depends on having solar panels to heat the water in the summer. In the winter we light the fire every day for heating, and that provides heat for the water, too.

The other day I had a shower and it seemed even feebler than usual. I had to turn the flow down to the most pathetic dribble to get the water anywhere near a comfortable temperature. I thought it was just because the incoming water is very cold, but Ian pointed out that it wasn't this bad when the outside temperature was -15°C, and concluded that there's something wrong with the shower. Since there was still some heat, we thought it most likely that one of two heating elements had burnt out. If we could replace that fairly cheaply, our electric shower could limp on a little longer, giving us time to plan a replacement. While I looked up replacement elements, Ian took the cover off the shower unit (after switching off the power at every possible point) to investigate. I heard a startled, Ugh! from the shower room. Was it full of water? I asked. No, mice!

Mice in the shower unit

Yes, that's right. There were mice in our shower fitting, snuggling up to the water heater. At least, presumably that's what they'd been up to when they were alive, which they weren't any more. This raised our hopes that the fault might be as simple as a chewed wire, but alas, there was no sign that the mice had done any damage before getting electrocuted.

In the meantime, I learnt that heating elements are not sold individually, but a replacement heater can assembly may be purchased... for £67.44. We could buy a new shower for not much more than that. OK then, it's not worth buying a replacement part for the old shower - perhaps now's the time to plumb one into the hot water system. This required decisions. The key question is how to get the water coming out at the right temperature. Trying to keep things as simple as possible, I thought that a manual mixer tap might do the job, as our hot water temperature is pretty stable. The alternative is a thermostatic mixer, but I'm not convinced by their reliability, and I assumed they'd be a lot more expensive. Ian looked to the internet to investigate the latter question, while I thought about what other information we might need.

Before abandoning the electric shower entirely, it would be nice to know that our system can supply enough hot water for a shower. It was designed to (by me), but not with much spare capacity, and we don't get the thermal store as hot as I'd originally expected to. Some testing would be necessary. Much as it pained us to take so much heat out of the store, it was the only way to get the answer.

Testing step 1: Run the shower at a desirable flow rate and see how long it takes to fill a bucket. Answer: 2 min. Step 2: Gather up enough buckets for fifteen minutes worth of water. Actually I only got seven; one was full of sloe wine, one was full of engine oil, and I don't know where the tenth is. Still, a fourteen-minute shower is close enough for testing purposes. Step 3: Run the shower at a desirable temperature and measure this with a thermometer. Answer: 39°C, which Ian cross-checked with advice online, and found to be much what everyone else says, which is reassuring. Step 4: Use the kitchen tap, which is a simple mixer tap, to fill the buckets, trying to maintain the same flow rate and temperature as we'd want from the shower.

There are two questions here: How easy is it to keep the temperature steady, and can the thermal store supply that temperature of water for the duration of a shower? The thermometers on the store at the start of the test read 60°C at the top and 40°C in the middle, which is somewhat lower than full, but quite typical in the morning after the heating's been on for a couple of hours. The good news is that the temperature held up quite well for the fourteen minute test. The bad news is that it was very difficult to maintain the temperature in the first five minutes. The hot tap may run at a steady temperature, but the pressure's all over the place, so I was constantly fiddling with the taps until it eventually settled down. That's no good. So much for a simple mixer tap.

Buckets of warm water. We left them in the kitchen so that as they cooled down, the heat would warm the house. It was also quite a good place to put a bowl of bread dough to rise.

Ian's research into thermostatic mixers wasn't very encouraging, either. They seem quite fussy about what inputs they require. In particular, he didn't think our system would be able to provide hot enough water - at least not consistently - for the things to work properly. Hmm, neither of the two options we were considering look very good.

On the subject of thermostatic mixers, we do have one in the system already. Ian's never been convinced that that's what it actually is, but after learning more about them he realised that it's probably just not doing anything most of the time, because the input water isn't hot enough. With the thermal store now hotter (the fire had been lit for some hours by this time), he measured the hot water temperature and found that it was 55°C. That's hotter than we'd ever want coming out of the tap. I reckon 43°C is about the hottest I'd want for doing the dishes, before I'd need to add cold to make it useable. That's not very much higher than we want for the shower. What if...?

What if we turn down the setting for household hot water to a temperature that's comfortable for showering? That way, we wouldn't need a mixer tap at all, either manual or thermostatic. It may seem a bit primitive to have no temperature control in the shower but really, we don't need the temperature to be variable, we just need it right. If the household supply can achieve that, why add anything else? The simplicity of this solution certainly appeals. We can always try it, and if it doesn't work well, upgrade later.

The next step was to plan the design and see what materials we already had available. We're not fussy about appearance - one day we'll make our bathroom nice, but that's a big job for sometime in the future, no point faffing about with buried pipework now. The plan was to insert a T joint into the hot pipe under the basin and take a pipe from there into the shower, attach a tap and fix it to the wall. The existing shower head has a standard screw fitting, so we can use that. We found a length of 15 mm pipe that had previously been connected to the old gas tank. If you watch the video in that link, at the end you'll see the man come over and tie a knot in the pipe. I had to cut that bit off. We also had a few short bits of 15 mm pipe, and various connectors.

The old gas pipe looked just about long enough, but until I'd bent it into shape, I couldn't be sure, so the next job was pipe bending. Ian was getting quite twitchy at this point as we didn't have much time before the shop shut (it being Sunday afternoon). I insisted that it wasn't worth going to the shop until we knew what we needed, and continued bending the pipe.

Pipe bending

It really was only just long enough to go over the shower screen and have one end low enough to clear the trap on the basin, and the other end low enough that the tap wouldn't hit the old shower unit (we're keeping that as backup. It's not good, but if the hot water runs out completely, it's better than nothing). Then we went and bought parts. All we needed were a tap and one elbow joint. I also bought a bag of olives - the sleeves that go inside the nut in a compression joint - because we have plenty of nuts and it would be really annoying to have to stop work for want of an olive. The total cost of parts was less than £10.

After that, and a tea break and chat to my dad (he called) it was just a matter of turning off the water then being brave and cutting into the pipework to attach all these bits. For some reason, our water wouldn't turn off completely, leaving it dripping. This is very annoying, but does provide an instant check for leaks.

I didn't finish connecting everything up until after dinner. I went round all the nuts, tightening them up and chasing the drips from joint to joint, until there was just one that was still leaking. I tightened further... the dripping increased. I went and slumped on the sofa in despair and Ian took over. He tried applying sealing gunk, but that didn't help, so he removed the offending pipework.

That would be the problem, right there.

The connector was cracked. No wonder it wouldn't stop leaking. Ian then went off and searched for more parts, and found another elbow that I'd missed earlier. Unfortunately I'd used the last of the PTFE tape on the previous joint and the gunk he'd already tried wasn't really the right stuff. And the joint was still dripping. He searched some more and found some very old jointing compound. It took a lot of scraping and stirring to recombine the solid and liquid parts, but eventually we had something that looked like it might be smeared on a screwthread. Ian did this bit, and put it all back together with the replacement elbow.

A hodgepodge of connectors under the basin

So far, no leaks! In the end, the pipework is even fairly neat...

... though perhaps less so at the shower end.

Yes, we did choose that tap.

So how is it, then? I had a shower this morning. I didn't really need one, but I had to test it, even though the thermal store was a bit on the cool side (we were too busy plumbing yesterday to pay full attention to the fire). The temperature, once the hot water came through, started at slightly hotter than I'd want but quickly dropped to slightly cooler. It wasn't uncomfortably cool, but didn't encourage lingering. That was OK, though, because the pressure was so much higher than I'm used to. I'm sure the flow rate was much higher than we used in the test, and not easy to turn down, but it was lovely! With that much water I can get clean quickly, so I don't need to spend fifteen minutes, and it's so much nicer.

We will monitor the situation, but so far this is a clear success. Of course, it does put the pressure on to get the solar panels finished before we stop lighting the fire in the spring.

Solar panels - Controller, mark 2

The postman brought an exciting package yesterday morning:

An SD card module, a liquid crystal display, some bits of wire, and a tiny little Arduino Nano computer (copy)

This meant that, first and foremost, I could replace the borrowed computer in my solar controller, and solder it all together so the wires aren't so prone to getting knocked out of their sockets. If possible, I'd like to use the little piece of strip board that I already have, rather than buying any more (yes, I am that tight with money). This makes the design quite tricky, as there's not much space to play with. I took a photo of the existing circuit...

Solar controller mark 1

... and edited it.

A plan for mark 2

Having got this far, I checked which Arduino pins I'd need for the SD card and LCD, and moved things around a little to free those up. This morning, I took a hacksaw to stripboard, heated up the soldering iron (I was going to write, Got out the soldering iron, but in all honesty, I never put it away), and applied solder as per plan. After moving things around, I found that I don't need the cut off piece of stripboard yet, but I will later.

Solar controller, mark 2
(photo rotated for comparison, which is why it looks a bit odd)

I'd like to have the sensors on plugs, so that I can unplug them if I need to take the controller out of the cupboard, for example to add extra bits. For the time being, I have short leads soldered to the board and I've twisted wires together to attach the sensors.

It's all connected up now and it seems to be working. The pump came on as soon as I switched everything on, but that's what I'd expect if there was no signal from the controller*. The real test was whether it would switch off when required. After toying with the idea of taking the glass off the panel to cool it down, I made myself a cup of tea, then took the tank sensor out of the tank and held it against the hot cup. A much more sensible test, and it worked. After that, it clouded over, so I didn't get to hear it switch on again, but so far so good. I'm now studying how to add the display and SD card, so I'm afraid you haven't seen the last of these posts.

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* I've wired it up to default to on to give me a manual override. If I plug the two parts in separately, I can switch the controller off and the pump on, if I want to. Obviously, I could also switch both off, if necessary

Solar panels - Controller, mark 1

For pumped solar panels, i.e. any that are positioned above the hot water tank they're supplying, it's necessary to have an electronic controller to turn the pump on and off as needed (unless, as we discovered with the basic panel, you're prepared to monitor it fairly closely yourself). This is a fairly standard bit of kit, and nicely packaged controllers with graphical displays can be bought for around £90 upwards. Less pretty, but just as effective, versions can be bought for about a third of the price.

The option that appealed to me most (i.e. the cheapest), though, was to make my own. Those nice people at REUK not only sell controllers made to your specification, they also provide instructions for making your own. I'd had this webpage bookmarked for some time, but when I checked back a couple of weeks ago, I saw that they have a new design. Instead of a simple comparator chip, the heart of the new design is an Arduino computer. Having spent much of my childhood helping Dad rig up various gadgets to our BBC computer, how could I resist having a tiny computer controlling my solar panels? REUK even have a nice tutorial explaining how to do it.

Arduino is an open source project, so whilst the official boards start from €12.00 + tax - which is pretty cheap for a computer - it is possible to get copies that are even cheaper. This is legitimate, provided they don't claim to be the real thing (though I think the Arduino folk would prefer people to do interesting things with their designs, rather than just making cheap copies). There are many variations on the Arduino board available, so I was a bit bewildered by the options. I girded my loins and set about reading, in the hope of learning enough to understand what I needed.

Luckily, there was a shortcut available. My friend Anita was visiting, and commented that her husband Dave would love my solar panels project. Ah... Dave... he's pretty hot on electronics, isn't he? Does Dave know about Arduinos? Yes. Why don't you come over for a chat? I did just that, and Dave was not only able to add the voice of experience to my deliberations - That one doesn't have enough pins... That one's good value, and it has a free cable with it... That LCD package has extra stuff with it, you can get the basic unit much cheaper... and suchlike - he also had several Aduinos, and was happy to lend me one to play with, along with a breadboard (thing for plugging electronic bits into to make temporary circuits) and the half-dozen components specified in the REUK circuit.

I went home feeling much more confident, and the next day I ordered temperature sensors (4 - I might as well get a couple of spares, while I'm at it), a power supply, and a relay from REUK, and an imitation Arduino board from some place in China. I also ordered an LCD display and an SD card socket from the place in China, because it would be kinda cool if I could also display the temperatures and record data, and neither was very expensive.

The items ordered from the UK arrived in a couple of days, and it was a fairly simple matter to plug a couple of temperature sensors into my borrowed Arduino, and the Arduino into my laptop, and get my first Arduino Sketch working. I was transfixed by the little light on the board, as I warmed up one of the sensors with my fingers to see the light to on, then cooled it by blowing to see the light go off. I could have watched if for hours.

It's all very well watching a little light go on an off - that shows the computer is doing what I want it to - but that doesn't help much with my solar panel. The next step was to rig up a couple of temperature sensors to some long wires (salvaged from the old washing machine. I know wire's cheap, but connecting pieces together gave me useful soldering practice) and put one in the panel and the other in the thermal store (tank). Connecting these up meant moving the control board into the cupboard. This required it to have its own power supply, as I could no longer run it off the computer in there, so I connected that up as well.

I do still need to connect it to the computer if I want to change the program, which proves a little more complicated than you might imagine. The only shelf in the cupboard is rather high, so I have to stand on a chair to reach it. It's also rather cluttered, so there isn't space to put the laptop down, and then I need two hands to connect the micro USB cable to the controller board, preferably without knocking any of the other wires out of the temporary circuit. I had to ask Ian to come and hold the computer for me.

Solar controller connected to temperature sensors

Although it's not very clear in that photo, there are two LEDs on the board, a green one that indicates when the power's on, and a red one that I'd programmed to indicate when the panel is at least 6°C (I've since increased that to 10°C) hotter than the tank. So far so good, but this still required us to switch the pump on an off, and the LED wasn't very easy to see, what with the shelf being so high.

The next step was to connect the controller up to the pump, via a relay. This part was a bit scary, as it brings me into contact with mains voltage (not literally, apart from that time I went to tidy up a stray strand of wire without turning everything off first). A while back, Dad gave me a soldering iron, some solder and a little bit of strip board. I think he meant me to use that to practise on, but waste not, want not, I went straight ahead and used it for the real thing.

A slightly wider view of the controller in the cupboard,
now with relay attached, to the right of the controller.

So there it is, doing its thing. It really does, too! We've had sunshine and showers for the past few days, so I've been able to listen to it turning on and off all on its own, as the sunshine comes and goes.

This part of the project has been almost disappointingly easy. With nice clear instructions from REUK, I haven't had to figure anything out for myself. I'm looking forward to my own Aduino-copy arriving, together with the display and card reader. When I have records of what the temperatures are doing, I'll be able to tweak the settings and see what effect that has. With my spare temperature sensors, I'll be able to look at things like how much heat is lost between the panel and the house, and how much difference insulation makes. In the meantime, though, I must get on with building the next solar panel.

Solar panels - a box

This has taken me longer than it might have done because I keep getting distracted by things like gardening and visiting relatives. Also, I had a nagging feeling that my design, such as it is, probably isn't very good. A friend recommended someone who could make a nice aluminium case, If you want to spend a bit of money. Well, yes, I'm sure an aluminium case would be good, but I don't want to spend money. Maybe I could treat mine as temporary, and upgrade sometime when we do have money to spend. At that point I started feeling better; it doesn't matter if my design's not very good, it doesn't have to be the last word on the subject.

Here we go, then. Not wanting to spend money on materials if I can help it, my box is made principally from old floorboards. I used lengths of 2x2 for the corners - I can't remember what we bought that for, but we evidently didn't use it. I kept the old radiator brackets when we took the radiators off the wall, so I can re-use those, too. Here's the frame, with brackets in place:

Framework of case for the first solar panel

The gap in one side is not for want of a long enough floorboard, it is part of the design. If water gets into the panel we'll get condensation all over the glass, which won't help efficiency, so I'd like to be able to let water vapour out, hence the vent. I don't want it open all the time, because air flow across the radiator isn't good for efficiency either, so I'll fit a sliding piece over the gap. That means ventilation will have to be manual, but it's better than permanently open.

At this point I would very much like to have put the radiator and glass in place to make sure they fitted. However, both these items were in service as a very basic solar panel which I didn't want to take apart. To move the radiator, particularly, would involve draining the system. Both items are heavy and unwieldy, and at that time, an awkward flight of steps away from the frame.

Ho hum, I'd just have to trust my measurements. This was unfortunate, as it was very difficult to measure things up there on the steep, slippery bank, especially the back of a radiator that was lying on the ground under a sheet of glass.

The next step was to insulate. I taped sheets of radiator backing between the brackets. This is the stuff that you can put behind radiators to reduce the heat lost to the wall, so ideal for this purpose. My friend Ellie gave me one sheet and the other I acquired from goodness knows where. I then turned the box over and added a layer of sheep's wool insulation, left over from insulating under the floors.

I retrieved a sheet of plywood that used to be the back of a fitted wardrobe. It was damp from standing against the workshop wall, so I left it in the sun to dry out for a bit. Once it was dry I cut it to size - most pleasingly, it was just long enough for the box. That's funny, I thought that last time I measured it, it was just too short. Well, it was hard to get at in amongst all the clutter in the workshop - I must have made a mistake. Here's the underside of box, with plywood in place:

Box from beneath

Before dinner yesterday, I applied creosote to protect the woodwork, particularly the legs. I put a coat over the plywood as well, even though it's been varnished before so it wasn't absorbed in most places. I'm sure it'll dry out eventually.

By this morning, there was really nothing left to do before assembling the pieces, which had to be done on the bank because the assembled panel would be too heavy to move. I woke up early, which was nice as I could make a start before the sun got high. I had to drain the system first, which is a pain because it needs the valve to be open but the pump off, which means disconnecting the wires to the pump. I remembered this detail just as I was applying flux to a solder joint, but I'm getting ahead of myself. Here's the insulated box in the early morning sunlight, with the glass ready to be fitted.

Hmm, that doesn't look quite right...

Pebble confirmed the matter: The glass doesn't fit. Oh, &*%#!

I went indoors and had breakfast. And tea. Tea makes things better. I realised that it doesn't actually matter very much if the glass sticks out a bit. I cut a couple of notches in the frame to accommodate the window frame, and left it at that. I'm sure I can stuff something into the small gap between the wood and the glass, so I don't have excessive ventilation.

Next, I checked that the radiator fitted onto the brackets. At first I thought they didn't line up, but it was just the angle of the bank, and my anxiety primed by the window measurement error. The radiator does fit, but getting it into position was one hell of a job. It's big and heavy. The bank is steep and slippery. It's not possible to see either of the two parts I'm trying to fit together at the time I'm manoeuvring them. This would have been easier with two people, but Ian was out driving a bus, and I wanted to get the job done so I could catch some of the sun's rays today.

Once I'd managed to get the radiator onto its brackets, and determined that it does fit quite nicely, actually, I marked positions of holes for the pipes. Radiator was removed and holes were drilled, then the box needed moving into position. This wasn't too difficult without the weight of the radiator, but I did need to fetch some bricks to go under one of the legs.

Before putting the radiator back in the box, I stuffed bits of wool into each end of the tubes on the back. This way, the fins will provide additional insulation instead of conducting heat away from the radiator, as they were designed to. I then fitted the radiator onto its brackets (which was a lot easier second time around), threaded the pipes through the holes I'd drilled and screwed up the fittings (thanks for the foresight to use compression fittings there, Dad), and reconnected my temporary plumbing. After mopping off and leaving it to dry a little (radiator not entirely empty) I put the glass back on.

While I had the system drained, there was one more job to do. At the end of the plumbing job, I was left with one tiny leak. It really was tiny and we were OK living with it for a while, but it should be fixed. I thought I'd have to take it apart and start from scratch, which proved almost impossible, but on the advice of blokes in the pub I learnt that it's possible to redo solder joints without taking them apart, so that's what I tried today. I'm not 100% sure, but I think I've fixed it. If it is still dripping, it's doing so far more slowly than it was before.

Plumbing concluded, I refilled the system. My temporary connections out on the bank are rather more leaky than they were before I took them apart and put them back together again. I can cope with a few drips, but I'll have to do those properly before too long. Nonetheless, I once again have a working solar panel, hopefully considerably more effective than it was before. Here it is, the nearly-finished solar panel:

Solar panel, functional again after only 8 hours disconnected, and, as far as we can tell from the temperature of the pipes, as much more effective as hoped.

I say nearly finished because there are a few bits and pieces still to do. It could do with a bit more creosote on the woodwork that's immediately under the glass and I haven't finished the sliding cover yet. It's also not in its final position, because positioning is a job in itself. Not the next job, though. The next job is the fun bit: The automatic pump controller.

Solar panels - pumps and plumbing

OK, here's the post that I meant to write a couple of weeks ago. Since the solar panels project is huge and daunting, I broke it down into sections: Making the panels themselves, mounting the panels in a suitable location, plumbing, and making an electronic controller. The last of these is the one that Dad finds most interesting, so conversations with him about solar panels tend to end up on that topic fairly quickly. For me, that's the least worrying (and probably the most fun) aspect of the project; I need help with the other bits. Having reduced, Mounting the panels to something less scary, my next most daunting part was plumbing. This was daunting because I'd never done plumbing before.

After dithering about and failing to get started for about two years, I called Dad and asked him to come and help. He spent a week here last spring and was hugely helpful. He put a lot of pipework in place, which was great, but since I didn't do it myself, I was just as much a novice at the practical side as I had been at the start of the week. However, going through the design and planning stage with him did teach me a lot, mainly about what's actually available in terms of different types of connectors and suchlike.

Our initial design had a pump and valve (very important: With no valve, the loop is permanently open, allowing hot water from the tank to flow out to the higher solar panels whenever they're cooler, e.g. at night) in the cupboard with the thermal store, then pipes running from here out of the cupboard, over the kitchen door, through the wall into the conservatory, along one of the conservatory roof joists, and out onto the hillside. There, we'd have the solar panels and a header/expansion tank. This last item is necessary to allow the water to expand as it heats; a completely sealed system would probably explode and I don't fancy dealing with the more high-tech alternative, a pressure vessel.

I'm never keen on spending money, so we salvaged as many parts for this as we could from things I already had. When I took the old central heating system out, I was careful to coil the microbore (10mm) pipes without kinking them if I could, so they could be reused. There was quite a lot of larger pipework, too, so we had plenty of pipes to play with. I found a spare header tank in the loft. There was a dead, dehydrated bat in it. I had an old washing machine that died of rust in the drum... or somewhere... it leaked, anyway. We salvaged both pump and valve from that (helpful having a dad who's taken many a washing machine apart in his time).

We spent the first day planning how it would all go together, and listing the various connectors we'd need. Bits were bought, pipes were connected, holes were drilled through walls, the pump was tested in a bucket of water, one radiator was painted black, and the system was assembled. (This was over a year ago, so you may be getting less detail than you would have done had I written the post sooner.)

Whilst I ended up with a much better understanding of plumbing and quite a lot of pipework in place, there were two main outcomes from that experiment: 1) A washing machine pump is not powerful enough for solar panels, and 2) The position on the bank where we'd put the header tank was not, in fact, the highest point in the system. This gave me two clear tasks to do next. However, once Dad had gone home I then caught up with various other things that I hadn't been doing while he was staying... then got distracted... and so it ended up being almost a year later that I got back to the solar panels project.

In the meantime, I had managed to buy a suitably powered pump. Being generally tight-fisted, I'd balked at buying an actual central heating pump and gone for a much cheaper aquarium pump instead. This may have been false economy. As soon as it arrived I saw that I'd made a mistake. The two nozzles shown in the photo were not an inlet and an outlet nozzle, but alternatives for the outlet. The inlet was covered by a grille. Evidently this was a submersible pump. Undaunted, I removed the grille and found a plastic ring that looked like something I might fix a pipe to.

Sometime later, I actually attempted to fix a pipe to it. My first attempt was a copper pipe around the outside with PTFE tape to seal. That didn't work. Fitting a pipe inside was more difficult as the impeller was fixed by three struts. Nonetheless, this was my next attempt: I cut slots in the pipe...

I cut three of these slots

... which enabled it to fit snugly into the pump.

Looks promising, don't you think?

This time I sealed it with glue and when I filled the pipe with water, my connection proved to be water tight. Unfortunately, the rest of the pump did not. Apparently, Water tight is not a requirement of submersible pumps.

Maybe an actual central heating pump would be necessary after all. We did have one - it was in the old boiler. Ian was very doubtful about its likely performance, though. He said it was making terrible noises just before the boiler stopped working altogether. Still, given the cost of new pumps, I decided to try this one next. It wasn't easy to get out - I think the last step in manufacturing that boiler was to rivet panels to the outside, so I had to cut a pipe to get at some of the nuts.

After a happy morning dismantling the boiler, I examined my pump. The first thing I did was to connect up the wires. It hummed pleasantly and I could feel a draught of air from the outlet. That was good - it seemed to be working. Next, I looked at the connections. I didn't fancy tackling the huge nuts on the pump itself, so I took it out with the adjacent bits still attached. As luck would have it, the connection on the outlet side fitted my valve perfectly, so that one was easy. The other one was much more of a challenge than it first appeared. It was a standard compression fitting with a nut that had 18mm stamped on it, so all I needed was a bit of 18mm pipe and an 18mm x 22mm reducing coupler. I had bits of pipe...

Part of the boiler, including 18mm pipes

... but the adapter proved surprisingly difficult to get hold of. Of course, it happened to be a Saturday afternoon when I was doing this, so trade suppliers weren't open, but I searched many websites. Having drawn a blank online, I looked again at that nut and noticed that as well as 18mm it also said Flowflex. I looked them up and their website didn't have any 18mm fittings either, but I thought they jolly well ought to have what I needed, so I sent them an email. After that, I couldn't do any more for the rest of the weekend.

Come Monday morning, I tried calling a local plumbing trade supplier, who expressed bemusement at my request, No... they're usually 15mm or 22mm. Yes, I know that. Usually isn't very relevant to the nut I have in front of me. I then checked my email and found a reply from Flowflex: Yes, we still manufacture 18mm fittings, but the problem is that we can not sell to the end user, but please contact Dan at First 4 Fittings, Daniel.jones 'at' first4fittings.co.uk I share this with you, only slightly edited to avoid Dan getting inundated with spam, because if you happen to need this information (and it's possible that the wonder of Google will have brought you here in search of precisely this), you will be very glad of it. An email to Dan elicited a quote for what I needed within about ten minutes. It wasn't even expensive!

A few days later I had my coupler, and a few other bits and pieces that I'd ordered at the same time, and I was ready to fit my pump. The only trouble was, I'd soldered the pipework in place to suit the aquarium pump. I skipped over that bit earlier but yes, I did soldering, and it didn't leak! Anyway, the pipe for the inlet side was not quite parallel with the wall, and also a bit low for where I wanted the new pump. I cut it back to make more space, but still needed a pipe running at an interesting angle into the pump. I spent some time assembling a wooden mount for the pump, including a wedge to fit between it and the wall. Did you notice that the 18mm pipes have bends in them? I decided to make use of one of these to get an upwards slope, as well as angling the pipe slightly towards the wall. The final arrangement should fit, but calculating and measuring felt like too much of a challenge. I'd have to offer it up, tighten everything up, then screw the mount to the wall wherever it ended up.

This presented a problem. If I tightened the connections fully, I wouldn't be able to drill holes in the wall because the mount would be in the way. If I didn't tighten them up, I wouldn't know where to drill the holes. Also, that pump is really heavy and it needs to go high up in the back of a cupboard.

This was my workspace when plumbing.
I had bruised ribs for days from leaning across that bar.

I called Dad for advice. He fully appreciated the problem of the heavy pump. Could you fix a piece of wood underneath to support it while you work? Well yes, come to think of it, I could. I fixed up a makeshift shelf and stacked various things on it - not all wood - to support the pump in the right position. This enabled me to line it up, tighten the fittings part way to make sure they wouldn't be under strain, make small adjustments, and then mark the positions for the holes in the wall. Then take it down, drill holes, screw mount to wall, tighten up connections and connect up the other end. Luckily, the other end was connected with a bit of rubber pipe, so I didn't have to worry about that too much. You can see the shelf assembly in the photo above. Here's a closer view of the pump:

That shelf isn't actually doing anything any more. I just haven't got round to taking it down yet.

I'd already got the header tank connected up (this involved cutting a hole in the ceiling and moving rockwool. Ugh) so at this stage I was almost ready to test the whole system for leaks. I just needed to connect up the radiator outside, which I did with much PTFE tape. I expected it to leak like a sieve, which wouldn't matter for current purposes, but surprisingly it didn't. Filling the header tank involved water spraying everywhere when I tried to connect the hose to a bathroom tap, then much going up and down of stairs and the ladder once I'd reverted to the outside tap connection. Filling the system involved raiding a spare light fitting for an electrical connecter block, and an extension lead. Without power, the important valve stays closed, so a section of the loop contains a large air bubble.

I was delighted to find that after tightening the connections a little more, there were only two small leaks. One I already knew about, in the plumbing that Dad did, and one on the outlet of the header tank, where I'd twisted it a little while tightening an adjacent connection. At the same time, I felt a little flat. Yes, I'd completed a major section of the work (well, almost. I still had those leaks to fix), but I had nothing to show for it. I've now fixed the leak in the loft (but not yet the one in Dad's bit) and you'll know if you've read my previous post that I'm now feeling a bit more enthusiastic about it. The next step is to make a box so I can insulate the radiator. I might even be brave enough to plumb it in properly.