Hi all this should be simple to some of you out there I have the heatslave 15/19 oil combi it's worked fine .it was taken out two weeks ago as we were having alterations it was re installed the other day filled up etc started up first time, after a few minutes it became apparent that no warm water was going through the pipes it clicked off as normal and the pipes then started to get warm but the burner will not re start. The pump works and the dial clicks when you move it to ask for heat .the burner does no attempt to fire and is not on lockout it's as if the whole burner has been taken out the rest of the boiler goes through its motions any thoughts