Whistling / kettling pipework driving me crazy

[T.C]

I had my boiler replaced with a Remeha 39c combi boiler a couple of months ago. since then i have had a high pitched whistling / kettle boiler type noise coming from one location of pipework immediately above the new boiler. The installer appears to have given up trying to rectify the problem and no longer returns my calls. That is why I am hoping a possible solution can be identified within the forum.

Through trial and error I have identified that the noise only occurs when certain radiators around the house are switched on. By closing the TRV's on 3 radiators the noise stops. If you open the valves even a little the noise starts straight away. The pitch of the noise increases as you turn on each radiator.

If it helps, the noise sometimes does not start as soon as the boiler is fired up. It sometimes gradually builds up in intensity. However other times the noise is immediate.

The installer previously inserted a product (unknown) which he thought would resolve the matter. I have recently injected Fernox super concentrate Restorer, and will be draining down the system at the weekend. It however does not appear to have made any difference so far.


The noise is starting to drive up insane, so if anyone has any suggestions of next steps.

Thanks.

 

[diamondgas]

TC ... Noise is either heat or mechanicaly related ... Your boiler is under warranty however. Phone up Remeha and ask for a call. If the appliance is the cause they should repair it under warranty. Or if nothing else they'll be able to eliminate the appliance so you can concentrate on the system? Hope that helps 🙂

 

[T.C]

Cheers for the reply Steve. The noise itself is not physically coming from the boiler. The installer did look at this with me to rule it out. However is it possible that something in the boiler could generate a noise elsewhere in the system? I had assumed not.

 

[diamondgas]

T.C ... another possibility is flow rate through the radiator valves. As TRV's shut down there's more and more pump flow pressure placed on the remaining radiators. This can sometimes cause a 'rushing' noise. Fitting an automatic bi-pass can regulate the flow through the radiators eliminating that problem ... 🙂

 

[T.C]

But would that cause the noise to occur in a completely different location on the system?

 

[diamondgas]

No the Auto bipass regulates the flow to the radiators keeping it at an even rate. As radiators shut down the bi-pass opens up keeping the flow to the radiators at a constant.

 

[SimonJohns]

Agree that a auto bypass should be fitted

 

[diamondgas]

Here's one DU146 Automatic Bypass Valve - Honeywell UK Heating Controls give's you an idea 🙂

 

[T.C]

Sorry if this is a silly question but my boiler (remeha avanta 39c) spec says it has an automatic bypass. Does this mean I already have one or is this something completely different?

 

[SimonJohns]

I'm sure it will also reccomened the fitting of an external one too

 

[diamondgas]

Sorry if this is a silly question but my boiler (remeha avanta 39c) spec says it has an automatic bypass. Does this mean I already have one or is this something completely different?

Not familiar with your particular boiler enough to know if it is self regulating? I doubt it though! Best folk to ask are the manufacturers. My own experience of boiler auto bi-passes are just throttles that are manually adjustable!

 

[Jonwells]

Being above the boiler may be a red herring, it maybe water hammer on uncapped or hanging pipework, I suspect installer has left old TRVs, the older TRVs are to be installed on reverse flow pipework. If he has changed over flow and return on the heating, you will get the valve seating chattering, on worn valves you may get it on valves even with thermostat head removed, remove thermos heads and try again, then go round and press in the "pack a day pin" on valve body until the noise changes pitch or stops, then change the valve or all of the, old style honeywell are the worst.