Grant outdoor boiler randomly turning on

[Gwynston]

Have an outdoor Grant Vortex Condensing oil boiler which is randomly turning on from time to time, burning for a minute or two and then switching off again.

I would be familiar with this behaviour sometimes in the winter if it's really cold as an automatic frost protection measure. But I don't know why it's doing it at this time of year when it's warm, outside of the scheduled operating times.

 

[tincup]

Id start looking inside at the 2 port or 3 port zone valves, room stat and tank stat.
HTH

 

[Gwynston]

Id start looking inside at the 2 port or 3 port zone valves, room stat and tank stat.
HTH

Thanks for the reply - but unfortunately this doesn't mean muchto me - apologies for my ignorance!
I wouldn't have thought the room stats or zone valves would have anything to do with it as I'm seeing this happening outside timer-on periods when the boiler shouldn't be active according to the control panel.
Our stats are set high enough that the heating hasn't even come on for 6 months - it's only the hot water heating that should kick in on the timer for an hour in the morning and again in the evening.
This just the boiler kicking in randomly by itself for a couple of minutes at inexplicable times....

 

[Terrywookfit]

Your stats need to be set low to prevent firing .

 

[ianmcd]

which Vortex external ? there are a few, does it have a setting to pre heat the hW store whether HW is switched on or not ?

 

[oilhead]

Is it a Combi?