Hi I have a Vaillant VCW GB 242 Combi boiler and every time I want hot water or heating (not so much of a problem at the moment) I have to reset the flame failure button - gas comes up and boiler works as normal whilst I draw water and then for a little while after. Looks as though flame / boiler trips out when not required instead of dyiong down and going to pilot. Any ideas of what problem is and if it is fixed easily?
The VCW is a very solidly built piece of Teutonic over-engineering. The over-whelming majority of problems seem to relate to the water flow diaphragm unit in some way especially the movement of the pin which drives a cam and a micro switch.
It is not clear from your description if EITHER the boiler trips out about 5-10 seconds after it has started (which means some sort of problem with the flame sense electrode/lead/PCB - unless the flames really are missing!)
OR The boiler carries on firing after the water has been turned off. Which would point to the water flow diapragm assy. I'm uncertain whether an overheat would also cause these boilers to pop out the black lockout button - or it's dealt with differently.
HTH
Ed
It is the second theory the lockout button pops after about 15 - 20 mins.
Ed Sirett wrote:
Please don't top post.
Does the button pop out after the tap has been turned off or after
15-20 minutes of normal operation?-- Ed Sirett - Property maintainer and registered gas fitter. The FAQ for uk.diy is at
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