condessing boler pressure gauge Help and information on all topics relating to your central heating, air conditioning and ventilation issues.

[frenchd]

when drawing off hot water or turning on heating system the gauge drops nearly to zero from its normal setting, this is accompanied by a severe tinny sound in radiators, any suggestions welcomed

[htg engineer]

What's the boiler make and model ?

With some boilers when the pump runs the pressure gauge drops by about 0.5bar. But theoretically the boiler should go to lock-out when the system pressure drops to between 0 and 0.5 bar.


htg

[frenchd]

this morning the system dropped to 0.5 bar and the system failed to come on, the make and model no are Baxi Combi instant 80 he, the ser no is LCH05283913.ABR78.
after adding some water to the system the bar reading rose again and the system started, i can't find any evidence of a leak.