Noisy hot water

[iain90210]

Hi,

I have what seems to be a standard residential set up with a pump in the airing cupboard driving both HW and CH systems heated by an external boiler.

I have bled the rads and the pump. There is no noise when only the CH is on. When the HW kicks in there is a regular 'flushing' sound.

I don't think this comes form the boiler circuit, I have bled it as stated. The pump seems to hum quite smoothly. It seems to come from water filling the HW tank. Can't think why as there is no water being drawn from the tank.

Otherwise system works normally. Any ideas?

 

[ChrisR]

They do make a noise sometimes. With everything off, let any air out from the vent at V:

 

[iain90210]

Thanks for the response ChrisR. Will have a look where you suggest and see if I get any joy.