We have a trianco oil boiler. The pressure kept rising to 3 bars and then venting out the back. the system then kept depressurising. The Valve was replaced as had split, and then had a new pressure vessel fitted. The pressure now rises to 3 bars with the hot water on and when the heating comes on the pressure stabilises before rising again. the pressure release valve dumps the water only when the heating and water is switched off.?? seem to be having a hard time finding an engineer who knows what is going on.??

Louise Simmons, March 2009

the pressure vessel on the system, probably not sized correctly, too small ,or boiler overrun not working

alanpotts, March 2009

I need to know more about your boiler is it a combi, as if it is then it would seem that the mains cold water coming into the heat exchanger is being allowed to get into the heating sytem water (not good) this cold be the heat exchanger seals or the heat exchanger its self how long has the boiler been fitted and how long has the problem been there?

Chestnut Plumbing (OFTEC), March 2009