"Rory" wrote in message
...

raden wrote
When a Suprima comes on, it momentarily energises the pump, this is
normal. It should also energise the pump on a daily basis to prevent it
seizing up during the summer

IMM wrote
It is best to have the pump externally controlled, so that when the
boiler
pulses the pump it really doesn't matter as it is running anyhow.
Also when the CH it on it is best to have the pump running continuously
and
allow the boilers burner to cut in and out.


Thanks for both replies - energising the pump is fine, it's the
momentary drop-out before energisation that appears to cause the problem
(of the pump speeding up).

IMM's suggestion accords with my own thinking - I believe I could
achieve this by simply shorting Switched Live and Pump Live on the
boiler (so the pump will run if the valves are open but will still
over-run too). Is there any reason not to do this - might it upset the
boiler controller?

I can't see any reason why it would. The boiler would switch the pump when
needed. If the pump is not running then it switches, if running, it doesn't
care. The temperature in the house will be a little more stable with the
pump running all the time when on CH.