my mum and dad have had there boiler go down and had an engineer out who could not get it working, he has replaced the module card and the wiring harness. I have had a look and checked that it was not external to the boiler I disconnected the thermastat controller and any other wiring in but the module card is still blowing the fuse. I am wondering if any one might know the problem. the boiler is a ideal isar HE 30 i think
