Ask a tradesman
Central Heating
Boiler pressure
Hello,
The pressure on my boiler Varys a lot from cold to hot. When it’s off and cold it’s just above 1. After a couple of hours it’s nearly peaking into the red at 2.5. I’m sure it didn’t used to vary this wildly.
Is it something need to get fixed or Is this normal?
Thanks
Tim
4 Answers from MyBuilder Heating Engineers
Best Answer
The expansion vessel on the boiler requires to be replaced or recharged.
Answered 2nd Oct 2019
It sounds like the expansion vessel in your boiler has either lost its charge or has failed.You would need a gas safe registered engineer to see if it could be re-pressurised or needs replacing.
Answered 2nd Oct 2019
Hi.
Your expansion vessel is either deflated or split internally. Both the vessel and prv should be replaced
Answered 3rd Oct 2019
this could be the filling loop passing, which is slowly increasing the pressure, or the expansion vessel may need replacing. the pressure gauge will always rise when the boiler is in use as hot water expands creating greater pressure in the system, then drop as it cools down. best to get this checked by a gas safe engineer to remedy this.
Answered 4th Oct 2019
