In message , OldScrawn
writes
A neighbour of mine (female) has a 10 year old PP, it's having spells where the
ignition sparks every second and you can see the flame size cycling up and down
at the same time. From a thread in 2001 it could be a break in the spark lead.
However their local corgi guy is talking about a failed gas valve but
apparently he doesn't really inspire confidence. If it were mine I would have a
play, but I can see this repair getting expensive, say if the guy replaces the
valve and then the board. My gut feel is that if they can't do a "cheap" fix
she should consider a replacement boiler. Or am I being unfair to Potterton?


By "flame size going up and down", do you mean that it's variable, or
that the main gas is coming on and going off again?

I can't remember if the main valve is a two stage one, but it is
switched by a relay on the pcb, either on or off.

If it starts sparking while it's in normal running mode, the pcb should
be switching the main valve off.

Loss of flame sensing can be caused by
a) a faulty pcb
b) a break in the HT lead
c) bad earthing
d) the electrode not being in the pilot flame (e.g. the electrode tip
breaking up)

--
geoff