Hi,

I'm having problems with my venerable but previously reliable Netaheat
MkII 16/22 boiler. Looking through the previous very useful postings it
seems as if the Spark Generator is failing, but I thought I'd ask here for
confirmation.

The boiler starts up okay from cold, and runs through a few on/off cycles,
either via the room stat or it's internal stat, but eventually it won't
relight.

When it ends up in this state, the air fan is running, the pressure switch
has detected this and the spark unit has 240v across it, but there is no
spark clicking away. However, the unit must have produced a spark minutes
ago to have lit the boiler previously.

Other than fit a new SG (approx £30 online, so not too bad) is there
anything else to check ?

I've tried starting from cold with the gas switched off (to check that the
thing will produce multiple sparks), and I've opened up the SG case but
there's no obvious signs of component failure. Maybe the capacitors have
dried out or something and it fails after being powered for a few minutes ?

Any comments approciated,

Cheers,

Phil Young