Gloworm 35ci combi - pressure fluctuations

[beardybikeboy]

Evening all
This here ******* boiler is rapidly becoming the bane of my existence since our house move in August. Various issues have gradually been fixed at great expense, but we're still having a bit of a wierd situation going on.
Basically the pressure in the boiler drops from 1.0 bar to 0.6 bar (thus the boiler doesn't work as it's below the 0.7 required) roughly every 36 hours. And yet at the same time, our overflow pipe seems to be constantly slowly dripping. It's as if the pressure gauge is telling the boiler that the pressure is too high, so it's bleeding the 'excess' off...and then of course it drops to below the necessary level. But I'm probably attributing the boiler with a personality and a mind of its own there, because I see it as a malevolent little demon sitting in our attic and eating our money.
Any ideas on this please? Much appreciated! Thanks

 

[ADS4GAS]

The Pressure relief valve (overflow pipe as you call it) is probably passing slightly. Sometimes a little dirt on the valve seating.

Does the pressure rise excessivley when the boiler is in use (this would usually indicate an expansion vessel problem)

The pressure relief valve is a safety device so therefore cannot be interfered with unless you are a RGI.

Hope this helps

 

[glasgowgas]

The pressure relief valve is a safety device so therefore cannot be interfered with unless you are a RGI.

behave yourself, ffs

 

[beardybikeboy]

Aye, the pressure is around 2.6bar when the boiler is on. I had assumed that was normal - heating water = higher pressure?
But what do I know. Cancer research, that's my field, not physics

OK - expansion vessel maybe. Something to aim the plumber towards. He recently replaced the pressure relief valve as the old one was dripping.
thanks for your help.