Boiler Pump Runs for couple of seconds then cuts out.

Hi

Have just replaced the thermostat, clock, and both pcbs on the boilermate2. All wiring is in good condition and fitted correctly to terminals etc. Now I have issues that the boiler pump is not operating.

The heating one is fine and boiler is on when I switch the power isolator switch back on but the boiler pump is not operating.

If I switch the isolator switch off leave it for a while with no power then turn it back on the boiler pump works but only for a few seconds and then stops working. Both pumps were replaced last year and center drive turns ok. Its as though something is tripping the pump out. I have looked at wiring diagram and given wires a wiggle to check for poor connections at the right terminals but still nothing.

Any Ideas or basic checks to help would be gratefully received.

Thanks

I think you have a faulty pump delay pcb. This is a link to the manual. https://www.unventedcomponentseurope.com/data-sheets/gledhill-boilermate-ii-2-manual.pdf

If you look at the wiring diagram you will see that the boiler pump is switched via the pump delay pcb (it makes it run on for about three minutes when the boiler to goes of to remove the last bit if heat from it and it stops the boiler tripping on overheat on some systems). You could try shorting it out temporarily I think it is connections 1 & 2 on the board but just check on the diagram etc. to be sure, pop the wire from 1 in 2 and see if the pump runs OK. I can repair the old pcb if it needs doing. see www.murraymartin.co.uk

Cheers Murray

Thanks for reply.

So do you mean wire from terminal 1 clamp on top of wire in terminal 2?

I looked at wiring diagram and saw live feed to pump comes from terminal one on that pcb.

Thanks
Nick

Yes put the wires in 1 & 2 together that should do it to test it.

Regards Murray

did the test and the pump is operating fine. Does this mean a 100% faulty circuit board?

Pretty much I guess. The pcb is controlled via the tank stat and any timers on the system (input to connection 4) you would need to see if you have 240v across pins 4 live in, and pin 3 neutral connection (do you have a mains measuring device) if so and there is no output then the pcb is fritzed. Regards Murray

Sorry terminal 4 is a permanent live to the pcb not switched. From the test you have done there is clearly a switched live coming into the pcb on pin 2 so highly likely that the pcb has a problem. Regards Murray

thanks will be in post to you tomorrow.

Regards
Nick