Might be worth checking how they are using it. If they're used to gas heating in a less well insulated home they may swich it off until they need it, whereas in

Might be worth checking how they are using it. If they're used to gas heating in a less well insulated home they may swich it off until they need it, whereas in a well insulated home with a heat pump you want it on basically all the time. edit: In-depth geeky video on this: https://www.youtube.com/watch?v=kGs_biFA87Q https://www.youtube.com/watch?v=kGs_biFA87Q