banging sound from boiler Help and information on all topics relating to your central heating, air conditioning and ventilation issues.

[BALLY]

I have a Baxi Solo 2 RS boiler for central heating and gravity feed hot water.Recently the boiler makes banging noises just after main gas cuts off when temperature is reached,4 or 5 deep sounding booms.The boiler is about 8 years old. help.

[htg engineer]

Are you finding the heating or hot water hotter than normal ? could it be over heating ?

Is there a pump over-run - maybe not working therefore the pump is stopping suddebly and the excess heat is trapped in the boiler.

[BALLY]

Thanks for reply.Have not noticed any increase in temp. in hot water or c/h . Pump-over-run circuit is not used in DHW Gravity Feed Systems according to Baxi manual.Pump runs while Room T/stat demands.Once the system has reached its required ( comfort ) temperature it is possible that the pump and main gas flame will stop running at the same time,making your theory about overheating in the boiler/pipes very likely.
But why now after four/five years of good service? BALLY.