I have a 3 year old Vaillant wall mounted gas boiler which works perfectly well with the front cover removed. When the cover is fitted again the boiler runs for a few minutes then cuts out again, take off cover, refire and all is ok? Grateful for any help.
If it's one of the condensing models (ecotec etc) then the air / gas ratio will be incorrect and need to be adjusted by a qualified engineer with a performance testing machine / telegan.
Ian
July 2009
sounds like either a fault with the flue or the venturi in the fan, best to get someone out who knows what they are doing.