Central heating pump running at random times?

[Templar]

Hi folks, i wonder if you could help me? My central heating system (about 4-5 year old worcester Greenstar condensing boiler with a honeywell controller and a grundfos pump) runs from about 06:00 until about 22:00 as per the timer. But over the past few weeks the pump has started running for short spells during the night? At maybe two or three in the morning, only for ten or fifteen minutes, but at the moment, we are not getting cold enough nights where it could be coming on for frost protection (night time temperatures never dipping below 10 degrees at the moment)

do I have a controls issue or could there be another reason?

Thanks in advance for any help you may be able to offer!

 

[Last Plumber]

Sounds like you need a heating engineer ( gas safe registered), sounds like a boiler issue

 

[Templar]

Really? OK mate, thank you

 

[Templar]

Really? OK mate, thank you

 

[Templar]

Really? OK mate, thank you

 

[JCplumb]

Are you sure it's the pump running and not just the boiler pre-heat?
If there's an eco mode on there, turn it on and if that stops the issue it's just pre-heating which nearly all combis do.

 

[Riley]

Don't think it's a combi mate

 

[oz-plumber]

If the Honeywell thermostat has batteries, try changing them.

Honeywell thermostats start doing weird things when the batteries go flat.
They are meant to have a low battery symbol that comes up, but have had countless experiences where changing the batteries in the thermostat fixes a lot of problems