Ravenheat Fan Combi Boiler CSI85?

is its the old model with 3 lights on the front panel?
If the fan starts and the bottom light illuminates, and then waits, its some thing to do with the pressure prooving switch, slow fan, blocked flue etc.
if the fan is starting to get tight (especially when hot)and therefore the case pressure isnt low enough, or "intermittent" not low enough, to trip the fan switch, then this will halt the firing sequence. the switch could be faulty. or the rubber hoses holed. or again a slightly blocked flue. This fault can also go as far as the burner igniting and then tripping out and cyclling on and off.

Andy Willett
March 2009

Works a treat! Thanks for the tip!

Andy
November 2008

When it fails to fire does it lockout? If so, my geuss would be a fault with the fan.
Early versions of this model had problems with the APS sticking. Giving the top right of the boiler a good talking to with your fist normally cured (temporarily) this fault.

Stephen
August 2007