i agree with ian (last post) specialy if the outlet pipe is located in exposed part of your property it happened to mine it frooze up and shut the boiler down, , you may also see the red flame failure lamp on,if this is the fault its possible you may see a small water leak on the first pipe on the left underside of the boiler due to the condensate water filling back along the pipe because it cant get away,if this is the case that the pipe is full up right back into the resoivour inside the boiler a quick fix without going outside would be to sw off then carefully remove this plastic 21mm downpipe and catch the discharged water that has built up back along the froozen pipe and then let it run into a tempory container (only about half a litre a day is discharged into this waste pipe depending on how many hrs a day the boiler is on) ,NOTE switching off & on again will also reset the flame failure lamp if it was on . good luck
David, January 2010
