Glow worm betacom 30c humming sound

[tommy1712]

I got a betacom 30c in my own house and this week it's started humming/whiring sound when hot water is drawn off, this sound is intermittent. The temperature is fluctuating also. We done the install about 5 years ago and maintained with inhibitor f1 yearly. My mate done the boiler as I am not gs (start training next month)
any ideas what might be causing this.
i doubt it's sludge as its a pretty clean system
scaled up plate heat?
high incoming main pressure as the mains were re done about 18month ago

Many ideas lads

 

[Riley]

Sorry mate you won't get any DIY boiler tips on here I'm afraid. I'm sure you understand why. I'd get your mate back, maybe you could work through it with him and get some evidence for your training

 

[Rickster123]

As above. No boiler repair advice will be given here. You could always put an ad here..[DLMURL="http://www.ukplumbersforums.co.uk/im-looking-plumber-gas-engineer/"]I'm looking for a Plumber or Gas Engineer[/DLMURL]