Running Pump.

I have a Boiler mate 2. Not many problems over the last 20 years. However the Boiler Pump is now constantly running. I phoned the Gledhil helpline and have changed the delay timer PCB and the thermostat. The neon light goes out as required but the pump never stops. The boiler is a Baxi Solo 2. It has just been overhauled and fitted with a new fan, gas valve, and PCB card. It seems to be working perfectly. Radiators very hot and plenty of hot water. Any thoughts as to why the pump is still running?

Could be the pump drive pcb stuck on. If you take the jumper off and turn it on it should click on briefly every few seconds or so then go off.

Thanks for your reply.
Have changed the PCB and it hasn't made any difference.

Sorry I told you wrong anyway the pump drive operates the heating pump not the boiler pump. There is a circuit diagram on page 14 there is really only the delay timer in the circuit on a quick glance. https://www.unventedcomponentseurope.com/data-sheets/gledhill-boilermate-ii-2-manual.pdf

If it was the cylinder stat you would expect the boiler to be running as well.

Maybe you got a dud pcb!

Regards Murray

Thanks Murray,
Just removed the link on the drive PCB and it works correctly.

Think you might be right on the delay timer PCB.
Gonna get another one tomorrow and hopefully that will cure the problem.

Its doing my head in tbh.

Thanks,
Will let you know.

I can repair you dud pcb's for you if your interested. £20 each or two for £30.

Regards Murray

I've renewed the delay PCB and still no change. Seems like I'll have to now sign up to B Gas home ins scheme.
Thanks for your time and advice.

Hi perhaps with a little more diagnosis it can be sussed, might involve disconnecting the odd wire to check what happens?

Murray

Do you have any means of checking for live connections, multimeter maybe or other mains tester?

The pump is driven by two sources according to the wiring diagram (although both use the pump delay pcb relay to energise the pump), the first is the cylinder thermostat via connection 7 which energises the delay timer, so when the cylinder thermostat is calling for heat the neon attached to 7 should also light up, the boiler should fire as well as the boiler pump running. What should happen then is that when the cylinder stat is satisfied and stops calling for heat the live should drop off of connection 7, the boiler will stop and the neon should go out. The pump would then run for a further 3 minutes to remove excess heat from the boiler before shutting the pump off. If the neon is out the boiler is off then the issue must be around the pump delay pcb if it still runs on after about 3 mins. Is it possible that the wiring is incorrect. The connections should be as follows. From Main connector 7 should go to 2 on the pump delay. Main connector 8 should go to 4 on pump delay. Main connector 11 should go to 3 on pump delay. Connection 1 on pump delay goes to live on the boiler pump.

Regards Murray