On Tuesday, 1 September 2020 18:34:05 UTC+1, RJH wrote:
On 31 Aug 2020 at 21:52:56 BST, "tabbypurr wrote:
On Saturday, 29 August 2020 18:50:11 UTC+1, RJH wrote:
My gas combi's sealed system pressure drops from 1.0 to about 0.5 bar every
few weeks. It seems to stick at 0.5, but I've not left it long enough to be
sure. A few seconds on the loop valve and it's back to pressure - so at
most a
pint or two of water.

I can't see anything obvious at and around the rads and pipework, but did
come
across an encrusted main water inlet valve/unions on the boiler. This was an
issue soon after the boiler was installed, and I've only just noticed it
now.
There's no sign of dripping water though. Could this be the cause of the
pressure loss?

I don't know whether it's the whatsit bottle or the valve, but encrustation
does indicate a leak over time.


Don't think it's either. The expansion vessel is at 0.6 bar, with a specified
range of 0.5 to 0.75. Nothing in the plastic bag on the overflow (after a
couple of showers and a few hours of heating).

While in, I had a closer look at the fitting and I'm pretty sure it's
historic, and no sign of any drips or leaks. The only other thing was the
condensate trap water looked very murky. That'll need cleaning at some point,
but it isn't the cause of the pressure drop.

So, under the floorboards for me. Joy.

Well, at least it's not time to dig up the concrete floor.


NT