replying to The Natural Philosopher, David R-M wrote:

Replace spring if possible - another fault is the micro switch sticking -
it happened to mine - took switch out - injected eltro-lube (or sim.
switch cleaning fluid) and worked switch many times - it freed off. Be
careful when replacing micro switch, as it can make the switch stick in
closed position if tightened too much. Valve now OK.
David R-M


--