My oil fired combi boiler is occasionally tripping the ring main. the first time it happened it blew the control box for the CH about 4 weeks ago. I've since replaced it but the RCD has tripped twice since- I,m pretty sure it is the boiler- it's just happened again this afternoon with very few appliances running when the wife ran the hot water. I've had no work done recently that could have caused this. I'm not sure where to start to fault the system :? , I'm a pretty competent DIYr. Can anyone give me some pointers or suggestions please?
Thanks in advance.