Hi
My Vaillant Turbomax 828E is making some very strange noises, before anything else, I'm happy to do work on the "wet" bit of heating but would ONLY use a Corgi engineer for the Gas/burner part. I'm just after some pointers to assist myself and the prospective engineer if it doesnt turn out to be simple.
The boiler is absolutley fine on hot water and when heating is warm, however when it is warming up it makes a noise that can best be desribed as snoring.
You can hear the gas valve open as part of the modulating sequence, the burner roars then subsides, i'm pretty sure it supposed to do this. When it is roaring, (max burn?) there is a vibration noise that almost sounds like air being drawn in. This noise cycles with the modulating burner, on for 5seconds off for 9 and it dies away slowly in between.
Things i've checked. Flue termination and connections, all open and clear, radiators bled and bled and bled, pressure ok and all rads doing what they should, expansion tank pressure ok, boiler drained and flushed, boiler pump bled, boiler auto vent removed cleaned and checked.
The boiler was moved 2 years ago by a corgi engineer who is now retired, after a phone call he confirms that gas pressures were checked at this time and the only modification was shortening the vertical exit flue by 12 inches.
As a potential red herring, the gas supply main in our area is being renewed at the moment.
Gas supply pipe is 3m from the meter, 22mm with a 10cm 15mm tail, also feeding gas hob. Flue is 1.2m long with a top hat.
Anyone got ant ideas? Is this kettling? It seems too regular for that?
Thanks John
