vailant vcw gb 221h pilot light?

yes replace the central heating over stat this will remedy the fault,to double check this is the fault when the pilot light goes out place your multimeter across the stat if it is faulty you will have a high resistance :)

santa's little helper
December 2011

these boilers have a habit of the burner preasure increasing it needs to be 5 mbar.

shauny
July 2007

You may be on the right track with the o/heat stat but if that's the case it could be over heating, not a faulty stat. It may be that the gas pressure is incorrect or the burner is not dropping to low flame.
You need to check these things first and then log what was happening just prior to the pilot outing. Were you running hot water? Full bath or just a little in the sink? Is the temperature control on the panel set too high?(by the way the 1-9 control is only for the heating not the water).
No point replacing more parts until you're sure what's going on.

T.h.s
June 2007

does it only go out when the boiler is running? have you checked the case seals are intact?

gary.wright53@googlemail.com
June 2007