probably air locked if you've been draining system. is the f+e tank allowing system to refill, did rads bleed ok. do you have a vent off point in cylinder cupboard.
iain, June 2008
thanks but it is not a combi boiler
john mannion, June 2008
Combi boiler? You'll have to increase the water pressure to around 1 bar by opening the filling loop before the thing will behave itself. Keep an eye on the pressure gauge and don't overdo it!
John, June 2008
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I can answer this question...
my boiler want start up classic lx ff fanned flue gas boiler?
