I hope the plumber sorts you out pretty quickly,
@dave r.
If you remember, I had a boiler repair done a few months ago. The engineer said at the time that there might be other problems and we'd just have to see.
It turned out that my CH system has a pressure leak too. I had to repressurise it a few days after the original repair and had intended to arrange a second visit but the pressure held up well that time. It lasted about 3 weeks before I could see
any pressure drop on the gauge, then there was a very slow drop for about 1.5 weeks. It got down to about 0.75 bar and then it lost what was left overnight.
I have been through this cycle twice now so it seems consistent. Obviously, the fault needs sorting out but I don't want to be told that a new boiler is required in the middle of winter so, if I can, I will limp through to the spring this way and get it sorted out then.
Another reason is that the engineer seemed completely unaware of the Covid-19 situation. No mask, no sanitiser, no hand-washing... I'd rather have my jabs
before letting him back into the house!
I'm quite intrigued by how this fault is manifesting itself. I have all sorts of theories, but I should find out for sure once the system has been seen to again.
I've been watching videos by central heating engineers explaining how the different parts of the system work. Interesting stuff.
I watched my engineer (from a good distance!) repressurising the expansion vessel . The vessel has a Shraeder (car tyre type) valve on the side of it and he used a floor pump to top it up to 1.0 bar. The pump was very similar to my bicycle track pump, only the hose was about 4 times as long so it could easily reach boilers mounted high on walls. It strikes me now that the Shraeder valve itself might have a slow leak. I've had that on bicycle inner tube valves. Some of the engineers in the videos sprayed a soapy liquid into the end of the valve. Any leaks would show up as bubbles. I don't remember my guy doing that. If he does it again, I'll make sure that he checks the valve. It might be possible to replace a faulty valve, but otherwise it might mean a new expansion vessel.
If the expansion tank lost pressure then putting more water on the other side of the diaphragm
would increase the pressure again but would be putting more stress on the diaphragm, and also there wouldn't be so much of an air cushion to absorb water expansion. (The reason for having the expansion vessel is that the water in the CH system expands when hot. Old-fashioned systems were '
open' so that was not a problem. Modern systems are '
sealed' so without the expansion tank, pipes might burst, or joints between pipes be pushed apart.)
I haven't been able to find any water leaks anywhere so I don't think there are any holes in radiators or pipes, but for the pressure to leak that slowly it would only take a minute pinprick of a hole so maybe leaking water would NOT be evident.
Anyway, enough of me rambling on about things that most of you are probably not interested in...
Time for me to get back to working on my game. I had it set up to work well on my phone, but it then occurred to me that there would be a problem with phones with different screens. A few tests showed that indeed to be the case. I spent a day getting thoroughly confused by pixel densities, aspect ratios, virtual viewports, automatic stretch modes... I THINK I cracked the problem at about 02:00 today but I want to carry out more tests after a few hours sleep. I only own one suitable phone, and at some point it will have to be tested on other phones, but for now I am emulating them on my laptop. (Oops, there I go again... Cruel people might say that I am
ALWAYS rambling on about things that most of you are probably not interested in!
)