Noisy Central Heating Pump

[davidjohnbarlow]

The Grundfos pump on my Baxi Combi 80e boiler continued to be noisy despite opening the screw on the automatic air vent when refilling the system. Loosening the large silver bleed screw on the pump while the heating was on released trapped air and stopped the pipe vibrating.

[Ed Sirett]

Is the noise a whine or a screech? in which case you have a damaged pump. The pump may be generic or it may well be that the head is interchangeable with a standard Grundfos unit.