On 19 Jun 2004 00:38:25 -0700, (Michael
Burrows) wrote:

Since we moved into this house 6 months ago our boiler has failed 3
times. On each occasion the problem is a corroded earthing plate in
the igition system. This is the part that the spark jumps to to light
the pilot.

On each occasion the fitter refuses to believe that the part was
replaced on the last occasion, its in such a bad state. I rang the
tech advice at Potterton and they say we should check the polarity.
Fitter did that and says its OK.

The parts supplier the fitter used says the new replacement parts do
not have a long lifetime - but 3 months?

Anybody got any ideas?
This is a very rare occurence. I'd look for other causes rather than
something electric like reversed polarity!. The netaheat is a fine
piece of kit and there are many still working. Apart from the
fortunately rare circumstance of explosion due to defective white
rodgers vales,they are a damn fine boiler.

joe