CH pump running on its own

Dec 19, 2007 11 Replies

Was woken up early this morning by what sounded like the central heating coming on. Upon inspection, the boiler itself was off, but the pump was wirring away quite merrily, despite the fact the heating wasn't due to come on for another hour or so.



Any ideas what could be causing the pump to run on its own?



Many boilers run the pump for a short while after the controls have shut off the boiler to cool the water in the boiler. Maybe the control circuit or boiler thermostat is faulty?

Davy

Many systems run the pump for a short while after the boiler has shut down to increase efficiency. Sounds like something in this timer circuit has failed.

Perhaps the boiler was on -- on a frost stat, either internal or fitted remotely somewhere? #

Some boilers run the pump periodically to stop it seizing. Mine does every

24 hours, for a couple of minutes. How long did your pump run for?

On Wed, 19 Dec 2007 05:06:16 -0000 someone who may be "Dark Angel" wrote this:-

In addition to what has been said, it could also be the first stage of frost protection. This will run the pump to circulate water. If things become even colder the boiler will come on as well.

OK a few more details.

The CH switches off at 1030pm, this was about 330am, an hour or so before it was due to come on (wasn't very happy about being woken up an hour earlier than normal either).

I checked the boiler, timer etc. Nothing else was on, only the pump which I could hear wirring away in the airing cupboard. Even when I set the timer to "off" it kept running, until I finally switched it off at the fused spur.

It wasn't that cold last night and I don't believe this has ever happened before, even on colder mornings so am not convinced its frost protection.

Pump ran for about 10 mins or so until I switched it off the system at the spur.

Not too sure what its been up to today as the heating is still on when I leave and is on when i come back from work, suppose if i get woken up in the night again i'll know.

On Wed, 19 Dec 2007 18:54:17 -0000 someone who may be "Dark Angel" wrote this:-

Though no useful details.

Useful details would include how the pump is controlled, the make and model of controls, settings and that sort of thing. Otherwise people can say little and the thought of a troll becomes more likely to be correct.

In message , Dark Angel writes

Well siknce you didn't have the presence of mind to say what boiler it is, it's difficult to give an authorative answer

Is it a Baxi Solo 2 ?

In message , Davy writes

Is there a frost stat in the system which had a short burst of on?

In message , David Hansen writes

No it's not a trolling style, is it ?

It's someone who would go into a car part centre and ask for an alternator for a blue car

Boiler in the garage? If so maybe frost stat switches boiler on and depending on the valve arrangment the water could just be circulating through a bypass rad and quickly reach 80 degrees or so and the boilers stat would switch the boiler off but the pump would keep going.

Keith

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