I have a Vaillant Ecotec plus 637 boiler fitted 2 years. I also went from a vented to unvented hotwater system and had underfloor heating fitted in a converted garage.
I understand the pump overrun is supposed to protect the boiler heat exchanger from damage but where does the heat go? Reason I ask is when the boiler burner stops and goes into pump over run every cycle, all my radiators and pipes start banging. This never happened with my other boilers and I have no idea what's going on. (All the radiators have had air removed and have been balanced. Also the TRVs are bi directional )
Does anybody have any idea what's going on?
Thanks in advance.
I understand the pump overrun is supposed to protect the boiler heat exchanger from damage but where does the heat go? Reason I ask is when the boiler burner stops and goes into pump over run every cycle, all my radiators and pipes start banging. This never happened with my other boilers and I have no idea what's going on. (All the radiators have had air removed and have been balanced. Also the TRVs are bi directional )
Does anybody have any idea what's going on?
Thanks in advance.