Vaillant VCW GB 242 issues.

[Stroudydad]

Only just found this site so first post here.

The boiler is an old vaillant combi that’s been here since we bought the house and to be honest other than a new fan and controller a few years back it’s never given us any issues.

The problem we have now is that the flame comes on for about 30 seconds and then cuts out for about 90 seconds when you’ve got the hot water running and a similar thing with the central heating except it’s off for about three minutes.
When it’s running the water get warm and the radiators start to heat but obviously don’t stay that way
As far as I can tell the fan is running as is the pump and certainly it’s lighting ok when it tries (except maybe the first attempt.)

any advice would be appreciated.


Many thanks,
Mark

 

[DP]

This is a boiler that is solidly built, operation is quite complex so majority of the wipper snappers will not even know where to start. You do not need a new boiler but someone who understands how it works and then can effect repair.

I have a client with two of these on their wall, I use to have one too. Posting where you are can help

 

[Stroudydad]

Thanks, I’m Gloucestershire..

 

[Stroudydad]

This is a boiler that is solidly built, operation is quite complex so majority of the wipper snappers will not even know where to start. You do not need a new boiler but someone who understands how it works and then can effect repair.

I have a client with two of these on their wall, I use to have one too. Posting where you are can help

I’m assuming from the fact it’s on for a similar period of time and then of for a period of time, but is quite consistent within a few seconds, it’s a temperature issue.. or possibly flow

 

[DP]

Anything is possible. Part of the operation is by servo action so difficult to say without being in front of the boiler. Boiler has some diagnostic lights and visual of component positioning can tell a lot. Even the gas valve operation is pneumatic and the flame is modulating for a boiler that age. Hasten to add, Vaillant had a modulating burner flame on previous model which now is hardly ever seen still in operation.