Whirring Glow-worm 18HXI

Now this is embarassing, but it appears our new boiler (nov96) has been making a whirring noise since it was fitted.
We live next to a pub car park and had attributed the deep bass whirring to a boys racer which his fat exhaust arriving and leaving the pub.
Turns out its the boiler.
The noise comes from the boiler itslef but its a system boiler so the pump is upstairs.
What is a causing this, trapped air? and its it really bad for the boiler?
I think its due for a service in nov but should I not wait til then.

My grateful thanks for your expertise (sp?)
Thanks
Tom

Forgot to add its only when the C/H is on, hence the long time for discovery.

Fog horn type noise? Usually caused by improper mixture which requires corgi man and flue gas analyser.

Wouldnt explain CH only though.

I assume you mean nov06 in which case glow worm may attend under warranty.

Its not a system boiler, its an open vent boiler A discontinued old Vaillant ecomax pro.

gas4you said:

Its not a system boiler, its an open vent boiler A discontinued old Vaillant ecomax pro.

Click to expand...

I think you really mean "its an open vented system boiler"

The boiler does not know if its supplying heat to the rads or the cylinder.

However, the heating load could include closing TRVs.

If you have TRVs try opening them all fully and then see if it still makes the noise.

Tony


PS I used to know a "Tom" in Oxford.

No I meant an open vented boiler, the pump is not part of it. These usually need the pump set on maximum whatever the size of the system otherwise they lock out for lack of circulation.