I have a Ocean alpha 240ec combi boiler, after filling the system to the correct pressure (when cold) as the heat increase the pressure guage goes up the more heat the higher the guage shows then when it goes cold the pressure requires filling again.Is it possibly the expansion tank requiring re pressurising and if so what would be the pressure?
thank you

dp, January 2008

Hi dp, How high does the pressure go when the boiler is operating and what pressure are you filling to when the system is cold. Is there any indication that the pressure relief valve is discharging water to outside. I would depressurise the boiler and check what air pressure you have in the vessel

D.R., January 2008