Changing Grundfos UPS 15/50x18?
I have an engineer coming to look at my system as the lower floor radiators have ceased to warm up. I suspect its the pump and the engineer says the system has to be drained down to change the pump but I thought it was a half hour job and didnt need draining down. Could anyone please confirm plus advise if there is a more modern replacement? Thanks for your help.
Mike, March 2013