Ive got a honeywell controller st699 which does hot water and or heating at the same time. |The pump is a grundfos and there is an elecric honeywell diverter valve. the pump and valve are only a couple of years old and seem to work fine, but Ive noticed that when I have both heating and water on at same time occasionally when the diverter moves to allow flow form one to theother there is a bang as a result of the water pressure or water flow direction changing, it isnt air in the system, could I have the pump running too fast?
Any ideas how to stop the bang. cheers
Any ideas how to stop the bang. cheers