Whistling from boiler when using hot tap

Simba-ali34

Hello,

I have a potterton promax combi boiler which has developed a whistling/kettling sound when turning on the hot tap.

The sound seems to reduce has the tap is slowed. I have also noticed this sound occurs when the boiler is turned off and the tap is running??

Any clues? Is this something a gas engineer could solve?

DaftyDuck

I've had similar on a new oil boiler, and it confounded the manufacturers. Unsolved it myself, slowly, by elimination.

Firstly, if it's just that hot tap, it may be the tap itself, and noise is referred back to the boiler, which magnifies it much as a trombone would. If all hot taps, I would still suspect the noise might originate elsewhere, but be magnified by the boiler. Remember, noise is just vibration.

Try turning up/down the cold water stopcock slightly... does it change the note or stop it? That's what mine was, a dodgy valve.

Another possibility is lime scale on the heat exchanger. Hard or soft water at your place?

Best thing you can do is really try to pinpoint the source. Try and feel for vibration, and try using a foot long piece of wood as a stethoscope.. unless you have a stethoscope handy!

A gas engineer might help, but I would try and pinpoint the source first.

Simba-ali34

So it happens on every hot tap but only when fully open. If I leave it half on it doesn't make the sound.

I can also close the cold water inlet on the bottom of the combi boiler which makes the sound go up or down depending on how open the valve is.

jefaz07

Will be the right hand hydroblock where the water turbine is.
Changed loads with a whistling/high pitch noise.

Simba-ali34

Sorry what do you mean by changed loads and is it an easy fix?

jefaz07

I have changed loads of them.

https://www.directheatingsupplies.co.uk/baxi-5116017-hydraulic-inlet-assy?of_tid=MFRWG5B5GEYDSJTGMVSWISLEHUZCM4DSN5SESZB5GE2TAOJT&adGroupId=42636234142&device=m&gclid=CjwKCAiAmNbwBRBOEiwAqcwwpUigsYPeluYOwsgl2wxoLFpHv69NKJIiNK_rWKWLBgWy3ETxz3oVZhoCMOsQAvD_BwE

Is the part, it is an easy fix.

Simba-ali34

What price range would a gas engineer charge parts and labour? Just a vague idea

Cheers

jefaz07

Perhaps £160
It may not be that, I just know that is an issue with these boilers.
It may well be the turbine only. Baxi claim you cannot buy them on their own, but the ariston ones fit, that would be cheaper again You can also get them on eBay.
Hard to know exactly the issue without standing in front of it.