temperamental Vaillant Combi

Hi I'm new
I have a Vaillant VCW-GB 242 EH combi boiler that is starting to act temperamental. Sometimes I cannot get hot water or heating, singularly and together, although I can hear the system trying to fire up. Sometimes pushing the flame failure reset button helps but not always. Sometimes there is no problem at all. The fault signalling lamp never lights up. Finally on occasio when system does fire up, it will close down after a few seconds the system is 6 years old ....................................????? can anyone help

bethkat

try the air press. switch they have had problems. look to see if it is black they are the problem ones.

forgive my ignorance....... air press ?

the system is 6 years old

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The Vaillant VCW 242 has not been manufactured for 10 years, so either the system is a good few years older than you think, or your boiler had been knocking around a bit before installation.

These boilers can be temperamental for a number of reasons, which require an understanding of the complex operation of the hydraulic system in particular. The previous poster referred to the Air Pressure Switch.

Check system pressure is up at about 1 bar, then have the bleed at the top of the main heat exchanger bled to exclude any air.

These boilers rely on a decent flow of boiler water so check the pump for operation & blockages, then it's a case of going in deep to check diverter valve is pulling over properly, etc.....