My combi boiler has packed up! I've had a leaking radiator which I've replaced today. When I've come to relight the boiler it is simply displaying fault code 04 (low system pressure) and refuses to reset. I've followed the fault finding guide in the manual and it simply says "replace PCB". Well, OK - but before I do, has anyone any experience of this fault that might just give me a cheaper route to repairing it??? I haven't tried to run the system with the pressure low, although due to the leaky rad it has kept dropping down - and I've kept topping up.... System is now at around 1.25 bar.
Cheers,
Dave