"hello I have a boiler valiant eco tec pro 28 and I have a problem with pressure gage it keeps raising when the heating is on to a 3.7 bar which is prity high, the valve that fills up with water is closed, I have try-ed to restart the boiler and bleed radiator to get to right pressure but it still raising up.
Anyone can help would be much appreciated many thanks

Hi

It sounds like your heating system EXPANSION TANK is defective and needs to be replaced. Here, when water is heated it expands and in a closed system like your boiler if there is not an expansion tank (or there is a broken tank) to ABSORB the expansion you will see a rise in pressure, especially as the water gets hotter, and in most cases the system will leak out the pressure relief valve.

Expansion tanks are about $35.00.

Mark

Some expansion tanks, like the one on my boiler, have an air valve to pump air pressure into or to let pressure out, if yours has a valve have you TRIED to relieve some pressure from it?