"Rory" wrote in message
...
Rory wrote:
IMM wrote:

Drat - it's not so easy. The controller sees this as a wiring fault
and
puts the boiler into lock-out. Now I look, this condition is in the
Fault Finding Guide.



Put a relay in. The boiler energises a relay which switches the pump.
Isolate the backfeed from the external switching from the pcb. A relay
for
£3 and base £2 from Maplin.

That would work as long as the controllers not doing anything
super-clever. Strange that it monitors the pump live at all, really,
because it can only go live under the boilers control. Perhaps I could
break the track on the PCB that provides the f/b!

Actually, I can't see that a relay would help - presumeably the coil
would be wired to pump live, so it would still pulse the pump as the
boiler fires. If I connect another live to the pump somewhere then
either the pump or boiler would run 24/7 and/or the boiler would still
see it as a wiring fault.

Maxie, will reveal if it actually "pulses" the pump. What length a pulse
is, is open to interpretation.