Radiators noisy when hot water turned off.

[christarry85]

Hi All,

Hoping you can help with a bit of a strange problem we are having with our system (Worcester Bosch combi boiler)

Whenever you stop running a hot tap, shower etc a few seconds later all of the radiators in the house make a creaking (expansion or contraction I think) kind of noise.

Have checked all of the obvious things such as system pressure etc but no joy so far.

Does anyone have anything else worth checking before I call a plumber?

Thanks,
Chris

 

[Armo74]

If the noise is also there when heating is on then you obviously have some pipes that on installation or when a new floor has been laid expansion room has not been allowed for. It can sometimes be quite deceiving where the noise is coming from.

 

[45yearsagasman]

Older WB combis will have a pump over run after HW operation which will dump excessive heat into the rad circuit until heat exchanger is cooled down.

 

[christarry85]

Older WB combis will have a pump over run after HW operation which will dump excessive heat into the rad circuit until heat exchanger is cooled down.

Hi,

The boiler is just over 2 years old. A greenstar 37 i think?.

The noise literally only happens when the hot taps are turned off and is in all radiators simultainously so I dont think it can be the normal expansion and contraction noises.

Just to add. No changes have been made to the system recently apart from topping the pressure up.

Chris

 

[christarry85]

Any ideas guys?

 

[christarry85]

Hi Guys,

Any ideas on this please? I will try and describe in a bit more detail.

If you either run the hot tap or the thermostat clicks off then 10-20 seconds later every radiator in the house simultaniously makes a creaking sound (almost sounds like it is cooling down quickly).

Does the boiler turn off the heating circuit when running hot water? If so it there some kind of valve which switched between that could be the issue?

I don't think it could be debris etc as I don't think this would affect every radiator at exactly the same time?

Heating and hot eater both work fine apart from this noise.

Thanks,
Chris

 

[danplumb]

it could possible be the diverter valve vibrating as it changes over, although i cant see this being strong enough to send shockwaves right around the system loud enough for you to hear, but cant see what else can be causing it apart from a pipe trapped with no room to expand.. get a engineer out to check your diverter if not start following your pipes.

 

[bolshy]

+1
Copper pipework?
Trapped pipework, tight radiator brackets/lugs on uneven walls etc on a system full of water transmits sound very well to all parts of it if the conditions are right. Your heating system IS cooling down when the thermostat is satisfied, or you run the hot tap on a combi boiler.

 

[Julienk88]

I have the exact same problem. Worcester combi compact cdi28
The engineer for gas safety come in 2w I will ask him and post here if he found the answer.

 

[ianmcd]

I have the exact same problem. Worcester combi compact cdi28
The engineer for gas safety come in 2w I will ask him and post here if he found the answer.

Well as the post is 0ver 9 years old he might have got it fixed, the engineer doing your gas safety will not be interested in it, that is not what they are there to do

 

[Julienk88]

He comes as part of my maintenance plan. The boiler was fitted a year ago so the installation is still under warranty. anyway I will post the outcome. somebody may have the same problem and will be happy to see the solution.