I have a full Evohome setup, controls UFH and individual room rads.

During the night, the pump (or could be the fan?) activates for 30 odd seconds or so, then quickly dies off and repeats this every ??-20minutes or so. The boiler does not fire - or didn't on the 3-4 cycles of this.

The system isn't calling for heat (BDR91s are unlit for hot water/ CH) but the pipes in the airing cupboard are warm from the system firing up earlier in the night (as per normal)

My son's room is kept at 17 degrees, and last night the room temperature was reading 17 degrees throughout the hour I spent scratching my head trying to work out why the boiler was activating the pump(?) or fan(?).

Sticking my head in the airing cupboard sounded like water was being circulated, but as I said the boiler wasn't firing. The pipes were slightly warm so the system had been on the last 30mins properly.

It did this 3-4 times before I eventually gave up and put a pillow over my head.

--> Now, could this be because the room temp was flicking above/below the room stat at 17 degrees? This causing the boiler to start the ''fire up'' sequence, then the temp would rise slightly, causing he boiler to start the ''shut down'' sequence....before the temp would flicker again and the boiler would fire back up....BUT...Evohome's controls preventing the boiler from cycling too often was ''regulating'' these on/offs?

How can I prevent this? Any suggestions on what could be causing it? Due to the boiler being near the bedroom these unwarranted activations are really bugging me at night.