I have a Potterton Netaheat 407676. As the system tries to fire up it blows the 1 amp fuse thats on the PCB controller. Is this a problem of the PCB controller. I have looked for a short anywhere but can't find one. I can get a PCB controller but I need to know if this can be the problem.

Mark Rigby, August 2010

if it's blowing fuses then you need to check the gas valve, fan and maybe the pump depending how it's wired. best way to test is to disconnect one at a time and see which stops it from blowing the fuse. if it's still blowing with those components disconnected then you need a new pcb. my money would be on the fan.

Ian, August 2010