Wickes Combi Pump Constantly Running

[simonk1969]

I have a Wickes Combi 102 boiler.
Everything is working on the boiler without problem(DHW & CH), however I have noticed that quite often the pump is continuing to run when there is no demand for DHW and CH timer is switched off. I've heard it running for literally hours at night when there is no demand on only the power light is illuminated on the boiler.

 

[GavThePlumber]

Not a diy job sorry.

Get a Gas Safe Registered Engineer in to sort it.

 

[chantelle]

I have a Wickes Combi 102 boiler.
Everything is working on the boiler without problem(DHW & CH), however I have noticed that quite often the pump is continuing to run when there is no demand for DHW and CH timer is switched off. I've heard it running for literally hours at night when there is no demand on only the power light is illuminated on the boiler.

If your boiler has a pump overrun facility then it sounds like a pcb fault.

 

[ianmcd]

Quite possibly a pcb fault but more likely a primary thermistor fault but as already advised this is inside the combustion chamber so not really a diy repair

 

[chantelle]

 

[chantelle]

 

[chantelle]

Quite possibly a pcb fault but more likely a primary thermistor fault but as already advised this is inside the combustion chamber so not really a diy repair

Thermistor monitors flow or return temps,why would this cause pump to overun when there is no flow or return to monitor? a thermistor does not activate a pump,it closes down a gas valve.

 

[bellairaphon]

Chantelle you are wrong I'm afraid. Thermistors have all types of roles within an heating system. Anti scale, frost protection etc. so these can cause the pump to run without demand.

Nath

 

[bazdaman]

Quite possibly a pcb fault but more likely a primary thermistor fault but as already advised this is inside the combustion chamber so not really a diy repair

Thermistor monitors flow or return temps,why would this cause pump to overun when there is no flow or return to monitor? a thermistor does not activate a pump,it closes down a gas valve.

Feel free to ask for advice on how basic components inside a boiler work, it must be hard for people with no experience to get their head around it

 

[D_Hailsham]

Feel free to ask for advice on how basic components inside a boiler work, it must be hard for people with no experience to get their head around it

But Mr C alleges elsewhere that he is an experienced installer.

 

[chantelle]

Chantelle you are wrong I'm afraid. Thermistors have all types of roles within an heating system. Anti scale, frost protection etc. so these can cause the pump to run without demand.

Nath

Don`t think I am,some thermistors tell the boiler whether to come on when the temperature gets too cold,frost protection, and the boiler will fire when the resistance reading drops below a certain point. Some thermistors monitor an anti scale function, (pump over-run) when the pump continues to operate until the temperature has dropped to a set temperature. YEEEEEEAWWWWN. Boiler not firing rules out frost protection, Like I said, sounds like a pcb fault, possible blocked heat exchanger if it has not been flushed/changed.Can`t see any of you disputing this. Next you`ll be asking me what an NTC or PTC is. Jurassic Park!

 

[ianmcd]

OP your boiler doesnt have a pump over run, the primary thermistor doubles up as a frost stat and brings the pump on, if the boiler doesnt sense an adequate increase in temperature then the burner will also light until an adequate increase is sensed, you can cancel this feature by turning the boiler control knob to off not just at the timer it must be on the control knob so try that.

Your boiler also incorporates a pump anti seizure function where the pump will run for 20 seconds every 23 hours if it hasnt been used, this is controlled by the PCB and will function with the control knob in the off position.

So turn it off when you dont need it at the control knob and come back and let us know whether the pump still runs or not