Potterton netaheat whats gone wrong?

[kordiun]

I have a potterton netaheat, been fantastic until now. Flummoxed most heating engineers. It started blowing the fuse on the psb. So a new psb, air prssure switch put in, still not working, so new fan put in, still not working. Any ideas please?

 

[Rob]

Gas valve?

 

[gas4you]

How often is the fuse blowing?

Has the switched fused spur 3 amp fuse ever blown as well?

Has anyone done any basic continuity tests on the few wires/connections off the ignition module?

 

[kordiun]

Wires tested using multimeter test ok. Both fuses were blowing when the timer switched system on. Now not blowing, pump sounds like its pumping but fan not working.

 

[gas4you]

Have you 240VAC coming into the boiler when there is a heating /HW demand?

 

[kordiun]

Yes, 240 V AC

 

[kordiun]

By the way, yes the 3 amp fuse blew too.