Loud noises in central heating system

[Jon Hill]

Hi,

Can you help me cure my noisy central heating system?

There is a rushing sound in the pipes when the pump is running and the pump seems to make more noise than it used to. Also when the motorised valve operates there is a very loud banging coming from the pipes.

The heating works ok and there is no air in the radiators. There is a bleed screw on the top of a vertical pipe in the airing cupboard and this collects a little air behind it every few days.

This problem may coincide with the fitting of TRVs I drained the system down and fitted them in the summer, the noise started this winter the system uses microbore pipe.

Are all the noises related?

Help please its driving me crazy!

Thanks in advance,

Jon

 

[Slugbabydotcom]

It does sound like you have some air in there! If the pump is fitted face up then undo the large screw on top till water comes out of it then tighten it up again. Have you turned your pump speed up? It could be dragging air through the vent. If so try lowering the speed again

 

[dal5band]

The thump on the valve closing may also be related to the pump being too high. I think you are supposed to leave one radiator without a TRV so there is a by-pass otherwise you can get a situation where all the TRVs are shut but the boiler & pump are still running, if the thermostat has not cut-off yet.

 

[Jon Hill]

Hi

Thanks,

I have left one rad without a TRV.

The pump has three positions its on the middle setting its always been on. It has a screw but the pump is fitted so the screw is on the side should the central heating be off when I loosen the screw off?

Would swapping the manual air bleed to a automatic unit help?

Can air remain in the system without ending up in the radiators?

Regards,

JOn

 

[Jon Hill]

The pump broke down yesterday, I have replaced it and now the system is quiet. Hope this might help someone else with the same problem.

Thanks,

Jon