I've read the ovation for this boiler's circuitry on this newsgroup, but
before I leap into replacing the pcb on mine I'm wondering if there's
something else causing the problem...

Symptoms a
every so often, while there is demand for heat the boiler stops; the
green light flashes ~twice a second, sometimes the red light is on,
sometimes off.

When the thing is in this state the water pipes coming out of the top
aren't paticularly hot.
Resetting may result in the thing firing, then after a few seconds it
goes back to the previous state.
Left alone it eventually starts working again.
I checked the heat sensor and it didn’t have a particularly low resistance.

So I'm thinking it's probably the notorious pcb.
Before I replace it can anyone think of anything else I should check?

thanks,

graham.