HW issues w. Vaillant boiler?

download the service manual from vaillant 1st. then look for dhw(domestic hot water) micro switch keep your eye on it and get someone to turn on the hotwater tap full to medium. know u should see a pin come out and push the micro switch to turn the boiler to run. if it does and nothing happens most likely faulty switch but vaillants have a common fault with there diverter valves which leak or have problems internal i would advise u change the complete divter valve use British gas as they charge £150 all in fee to fix any boiler including parts which is a service for non members and if the can not fix it they dont charge a penny a plumber like me will charge £200 plus as the valve is £130

kash
August 2010