Mid position valve – The final chapter

Ok, after eventually getting up I stripped the valve down properly this time. The mechanism was all a bit bent and the micro switches were missing the blades, this was all probably down to years of heat expansion / contraction though. Nothing really wrong that a bit of plier manipulation and some WD40 didn’t sort out. So then it was on to the actual valve bit itself. It has very little movement, probably 30 degrees at best. So I attached a big adjustable to it and forced it over to the B side, which is water only, I then fired up the boiler. With my posh new differential thermocouple machine I was managing to get a temperature differential of about 20 degrees, so that all looked fine. I then moved the valve over to the A side, which is heating. This is where I thought I had a big problem as I wasn’t getting much of a differential at all, plus at times it was actually negative, so the water was hotter than the heating. I checked all the valve again, free movement, so I was thinking the valve was leaking on one side. Then I had lunch, and that visionary moment, where you think, ah yes, big tit. So what was actually happening was quite simple. On the A side of the valve is the nice very long collection of pipes doing the heating, containing many litres of water. On the B side is quite a short loop just going to the water tank. The water tank contains about 60 gallons of water at about 55 degrees. So what happens when you move the valve to the A side? Well the B side now just contains stagnant water, which is being heated in a massive heat exchanger in the water tank. So as there is no flow, the water tank will now be heating the water, not the boiler, it’s all acting in reverse. So what I did was turn off all the hot water heating on the programmer, then throughout the day I just used all the hot water as normal. Then sure enough when the heating comes on I’m now getting a 30 degree temperature drop across the valve as the B port pipe now contains nothing but cold water. So finally in conclusion, apart from the actuator being a little big old and knackered and could probably do with replacing at some point, there is actually nothing wrong with the valve at all.

Went to Tesco’s picked up food as mother was coming to dinner. Then spent the afternoon in a mixture of cleaning and wine making. I bought a kilo of Strawberries and a huge bag of sugar. Then using my new wine making stuff I proceeded to make a Strawberry fruit wine. Well I now have a bucket of fermenting something or other anyway.

About to have a shower when I decided to go outside and tell the taxi that was waiting that he should actually be at my mothers rather than my house, he read the source and destination the wrong way round. At least that company is cheap.

Jamie was finishing at 8, mother arrived just after 7. I must admit both her and the dog were very well behaved. She only came out with a few dull anecdotes. Managed to get her on a good quality red wine and she enjoyed the food. She only gets fed once a year so good she enjoyed it.

After she went Jamie decided it was then a great time to put the Sonic Meccano together. Getting stickers on the right way round after a couple of bottles of wine was an interesting challenge. Still good fun had by all.

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