6 years ago I replaced my old conventional boiler with an Ariston 15rffi system bolier. My house is an average 3 bed semi with 7 room rads. However for a couple of years now, when the central heating is turned on the boiler switches off and has to be reset so no HW or CH. I've had the gas board out several times but the problem persisits despite a new pump being fitted. The boiler is only 6 yrs old and is only being told what to do by its electrical system. ie "shut down theres a problem", but I cannot find the problem and nor can anyone else. Any ideas out there as to what can be causing the problem. The CH system has recently been powerflushed, No visible leaks. I'm thinking of biting the bullet and replacing it with a Combi system.