On Mon, 03 Mar 2014 21:44:01 +0000, Mike wrote:
> Has anyone else had this problem and what did you find helpful?
Similar sort of problem with the same boiler, yes. Turned out to be the
cheap and nasty Chinese relays they use. Try exposing the control pcb and
gently tapping it whilst listening for the characteristic relay 'click'
followed by the pump cutting out. Then you'll know for sure it's a relay.
However, sometimes there's no 'click' but the same thing happens anyway.
In both cases, it's a relay. Even when the relays are energised and the
contacts appear closed, they can still be open circuit as they often
don't close with sufficient pressure to pass current.
If Worcester-Bosch had used decent relays, it wouldn't have added hardly
anything to the final price, so it's a shame. A service bod won't bother
trying to trace a faulty relay, however, he'll just swap out the whole
board (90 quid odd) and charge you for that plus the labour etc. If
you're handy with a soldering iron, you can save a worthwhile sum just
replacing the duff relay(s).