Noisy central heating pump

[Andy Velcro]

Hello

I'm having trouble with my central heating pump making a rumbling noise! It sounds to me like there is air in the system even though I have bled all the radiators. There is a pipe between the pump and the storage tank which has a nut on the end of it, is that a bleed point for the system? Is there a certain way of using it?

Thanks in advance for any help.

 

[breezer]

I am not a plumber or heating engineer, so i guess the nut you refer to is a pressure release valve, but to bleed the pump you slowly undo the big screw in the middle of it (just like a radiator stop when water comes out)

 

[Andy Velcro]

Thanks for replying. Do you undo the nut in the middle of the pump when the pump is running or off.

Cheers

 

[breezer]

you should only loosen it , and it should make no difference, but i would say off