Ariston Euro Combi not reaching pressure - any ideas please

[EliTom]

No sign of an active leak there. What about the Schrader valve on the expansion vessel? If air was leaking from that it would appear as a drop of the system pressure. Also are you sure that the flow and return iso valves are fully shut? If so, you must be losing water somewhere from the boiler. It can't be that difficult to track it down.

Thanks Chris

Firstly the expansion vessel in brand new today, because yesterday it showed a pressure of only 5psi.

I cannot honestly see any signs of a leak. I will look again, but really all appears dry.

Do I take it that the photos posted are nothing to get really worried about. Is this normal in this age of boiler?

Just checked the pressue and now down to 0.3 barm but all dry as far as I can see. Will check it again with a bright light.

Any ideas where else to look?

thanks again

EliTom