Bump again! I have a new, unrelated boiler problem.
I have an Ideal Logic Combi 30, and it’s just started losing system pressure. I’m used to topping it up once or twice a year, but it’s just started depressurising every day.
I noticed the pump was quite hot, so I tried bleeding it off, which hasn’t worked.
Next focus was the expansion vessel, which I think might be knackered. I shut off the in and out valves, drained down the boiler and pressure tested: next to no pressure. However, every time I tried to pump pressure into it, it would get to about 0.5bar and I would hear two clicks, like a pressure release valve opening and closing, and the pressure would drop right back down. The static pressure should be 0.75bar.
Does this sound like a knackered expansion vessel or am I barking up the wrong tree? Could it be that my pressure gauge is not accurate? Does the expansion vessel have its own pressure release?
Many thanks in advance.