CH Pump Problem

[nobby]

I've just fired up the central heating in my house for the first time since I moved in, having had a few radiators off for decorating. I've been round and bled every radiator in the house but only the upstairs ones are getting hot. The pump seems to be working but it is quite noisy (not screeching or grating, but loud humming and whirring).

The pump is a roughly 1995 Myson Compact CP53 (looks identical to the Circulating Pumps CP53 sold by Plumbcentre). I can't find a bleed screw on the pump itself - could it have an airlock? How do I bleed it? Or is it just knackered?

The pump is mounted vertically in the airing cupboard, with a 3 port valve at the top, one side going to the tank, the other to the radiators. On each of these connections is a bleed screw, and I've bled the air out of there as well.

Any ideas?

Cheers,

Bob.

 

[ChrisR]

Circulating Pumps pumps ARE Myson pumps - so yuo'donly need to change the body. The big central screw bleeds it , but if the pipe's vertical you won't need to.

Try closing the upstairs rads to just 1/4 turn open, and work from there

 

[nobby]

Thanks Chris, I'll give that a try.

I've removed the pump and stripped it down - looks ok, not too much oxide deposit, but the impeller can be wobbled from side to side by 1-2 mm, which I guess is not normal?? - would that suggest the bearings are shot, accounting for the noise.

 

[kevplumb]

probably try a new pump

 

[ChrisR]

yeah that's too much play. they go in and out an alarming amount though!

 

[kevplumb]

na not going down that road