FB Combi90 LimitReset

[vhooda]

Hi,
I have a firebird combi 90 which needs limit reset button pressed after every couple of hrs of CH operation, the relay gets pulled in and boiler does not fire until limit reset is pressed, once limit reset pressed it starts perfectly, I also notice that turning ch temp thermostat down does not really make any diff to how hot the radiators are getting. Also expansion vessel seems very heavy thought still got air in it. Any ideas!!

Thanks

 

[Boilerman2]

Get an Engineer in to investigate and service the fault could be the hot water store stat, the boiler control stat or even the Limit stat, only physical testing will confirm which is at fault -Heavy expansion vessel= lack of air, or the vessel is too small for the system!
only a site visit will answer your questions!