Combi boiler with Drayton LP20RF & DIGISTAT+RF - upgrading to programmable or smart thermostat

grumpy_codger

I presume your boiler display will give CH delivery water temperature readings when it's running? It'll be interesting to see if you notice any difference in behaviour - boiler running for longer and cooler once up to temp, and things like that. Rads being kept at a mid-temp rather than cycling on and off.

Yes, the boiler displays the water temperature. I didn't pay much attention to this in the past (heating was OFF) so can't compare, but I do see that the boiler doesn't use the maximum power available and when the set temperature is close, water gets cooler gradually and the radiators remain slightly warm when the temperature is reached. In the photos the red curved bar at the top shows the heating power ATM.

What does the geofencing do? Turn down the CH if you leave home? Turn it back up as you return?

I think the thermostat follows the schedule when someone is at home and switches to the set "Away temperature" when everyone leaves. With my previous Honeywell it was either schedule or geofencing with two set temperatures for the latter (ETA: three temperatures in fact - 'away' and two for 'at home': 'day' and 'night' with adjustable time for the latter).