The pilot light of my aging (but previously very reliable) Ideal Mexico RS65 CH boiler will re-light, and flame is blue (no yellow) but looks a bit on the small side. When main burner cuts in, the gas valve very quickly closes - presumably because the pilot light isn't generating enough heat for thermocouple to keep main valve open - and all flames go out.
Assuming that the underlying problem is with the gas supply to pilot:
How do you clean pilot light/clear jet if blocked? or is it more likely to be gas valve itself/something else?

Nigel Homebuilder, November 2009

You need to be gas safe reg to work on this repair... remove pilot injector and place into small cup of boiling water. remove and dry out...replace and all will be ok...or you can just get new pilot injector.... another possability is there is a pressure drop on gas working pressure

darren ( gascare ) s-o-t, November 2009

new pilot injector and pilot spreader will proberly cure this dont try cleaning the injector by pushing things into it as this is set to correct size and this can affect performance is there a pilot adjuster on the gas valve google the gas valve this will tell u.

sean, November 2009