Thursday 24 May 2012

Managing not to set the house on fire

I've been using up some leave not boating, but doing jobs in and around the house. Some time ago I replaced the hot water cylinder (I want to call it a calorifier) in the airing cupboard with a twin coil one (just like on the boat). This was to enable solar heating of the domestic hot water.

The solar panels are on the roof; the hot water cylinder is plumbed in to the original boiler circuit; and all (All!) I need to do is finish off connecting the solar circuit.

I'm sure it's the sort of job which would take a plumber half a day, but I'm doing it very slowly. I have to think about where each pipe is to go and where it needs bending, cutting or connecting.


The top photo shows the expansion vessel mounted in the airing cupboard, with what looks like a trombone connected to it. Don't laugh: the instructions said it needed a metre of horizontal "dead leg" before connecting up to the rest of the pipework, and the only way I could get it in the space was to fold it a bit. I hope all those solder joints are sound. It had been a while since I last soldered copper pipe, and I made the mistake of assembling it all before soldering rather than adding each length of pipe and soldering it one at a time. The problem with the former method is that, as the lengths are short, heating one joint burns off the flux from the next, and so the solder doesn't flow properly.


The last job I tackled this evening was a tricky T-junction about an inch from the ceiling. (I'd learnt my lesson - I soldered each of the three pipes into the T as three separate exercises.) The difficult bit was making the final connection, that of the pipe coming down from the loft. How would I heat the joint without setting fire to the ceiling (lath and plaster)? My heat resistant mat wouldn't protect it as there wasn't room. So I had the idea of stuffing some of the loft insulation around the pipe. First I tested a piece for fire resistance on the gas hob. Good - it didn't seem to burn. Then I wetted the laths in the loft in the vicinity of the pipe, and made a water fire extinguisher out of an old squeezy bottle. With Jan watching on I lit the blowtorch and applied the heat to the joint. Of course, with three pipes now connected, the joint took a lot longer to heat up before the solder would take, and I was worried about what might be happening in the loft. The ceiling in the airing cupboard didn't seem to mind getting hot, though. As soon as the solder started to flow I hurriedly finished off the joint and rushed up the loft ladder to see what was happening up there.

Fortunately my precautions seemed to have worked as there was no smoke - and certainly no fire! Phew! You can probably see the blackened fibreglass insulation where the pipe goes through the ceiling.

Well, that's the difficult bit done - until the next difficult bit. Still got to connect to the coil, and there's a fair amount of crawling around the loft to come.

I really want to get this all finished now - but it will have to wait a little longer. There's boating to be done! And not much time left in which to do it before Ally and Ben move in.

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