Whistling Boiler on DHW Startup

[Hadventure]

For around six months my Vokera Vision 25C has been making a short whistling noise when the hot tap is turned on. It started intermittently initially but now its everytime hot water is called for. I can’t recall any works to anything when it started. The noise lasts for two seconds max and I assumed it would be fixed at service.

Well today it was serviced. The engineer opened and cleaned the insides, the noise was still present, removed the DHW heat exchanger having drained down the boiler and washed that in the garden – noise still present. The heating system magnetic filter was emptied, inhibitor added and topped up, all radiators bled. Still the short noise.

The noise is not present when the heating is on. It is only present for two seconds shortly after the hot water is turned on. If you leave the hot tap on then its fine until its turned off and on again and the noise returns.

It sounds like a wet finger on a glass of wine and I have some recordings. It seems to be coming from the flue as its almost as loud outside as inside.

My boiler engineer is old school and says he will look into it / call Vokera. I thought I would post on here to see if anyone had any suggestions. I filmed two videos whilst he was here so you can hear the tune first hand. Any advice would be well appreciated.

 

[SimonG]

I would say it's something to do with the boiler being at max when it fires for hot water. I would have thought your service engineer would have been able to resolve.

 

[Aquarius]

I can’t playback any sound/file. Does it make this noise at all taps?

 

[king of pipes]

Needs a GSI to analyse the flue gases and adjust as necessary when was it last serviced ? If it's more than 12 months it needs doing . Kop

 

[SimonG]

Needs a GSI to analyse the flue gases and adjust as necessary when was it last serviced ? If it's more than 12 months it needs doing . Kop

Serviced the other day, that's why couldn't understand why it wasnt fixed.

 

[king of pipes]

Serviced the other day, that's why couldn't understand why it wasnt fixed.

Maybe it was adjusted but not tested at high and low rate ?? rate

 

[Hadventure]

Thanks for the replies. I will ask whether it was tested at high and low rates. Is that difficult to do and adjust? I.e. should I be getting a Vokera Gas Safe specialist in? Yes it makes the noise at all hot taps when hot water is turned on.

 

[king of pipes]

A gas Safe engineer .

 

[Hadventure]

A Registered Gas Engineer .

Thanks - the guy who serviced it was registered gas safe. So I take it anyone registered gas safe should be able to fix this?

My question was when I go to Vokera's website they have their own list of registered Gas Safe Vokera specialists. Is it worth having a Vokera specialist (registered of course) look at it?

 

[king of pipes]

It wouldn't hurt but any Gas Safe registered engineer should be able to fix this 😉 Regards Kop

 

[Brambles]

It is a known problem with the Vokera Vision range. Once your GSR contacts Vokera it is a replacement part and a 20 minute fix. Alternatively Vokera will come out to resolve it.