A couple days ago i went to throw the heating on with no such luck. i tested my hot water worrying it was the whole boiler knackered again but that was working fine. the wireless thermostat receiver is showing alarm, so i replaced the battery's but its still showing. following advice i pressed the override button understanding that would be the common fault an should fix the problem but again no CH. if anyone has any ideas on what else could be the problem id greatly appreciate the advice!? Cheers Craig.