Hi CharlieW,
It is possible the the new capacitor has failed. That would be back luck - but it is possible.
If you can test the voltage...
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Same as everyone else, changed the cap, 0.68uF and all is well, for your info the fault i had was green light would come on but you couldnt hear the relay click nor would the boiler fire, easy way to check is the coil voltage before replacing the cap was approx 9V, after changing the cap it was back to its normal 24V
Good luck
Dave - Cardiff
September 2011
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... If SCR and wall thermostat are communicating, with the green light triggered on/off by wall thermostat control - I'd still be suspecting the capacitor, and at only £2.38 from Maplins, I'd try soldering another capacitor. I've bought a couple of spares - no longer a Maplin stock item, so "when they are gone they are gone."
The SCR should fit snuggly back onto the wired plate fixed to the wall. Maybe the contacts are not being met between wall plate and SCR housing... if this were the case the signal would reach the SCR from the wall thermostat but the boiler would not get the signal to fire up/shut down via the contacts.
Carefully check the wiring from the SCR wall plate to the boiler (both ends). Check there is a voltage at the boiler end.
If it's a combi and turning the hot tap on triggers the boiler to fire up and supply hot water I would be looking again at the SCR, then the wiring from SCR to boiler.
Good luck.
NigelR
NigelR
October 2011