Got to try this!
There was a great letter in The Times this week from a chap complaining that when the tenant in the flat beneath his is at home he can turn his heating off and just enjoy the warmth emanating from the flat below.
Unfortunately, the man in the flat downstairs is away a lot, and rather unsportingly declined to leave the heating on in his flat whilst absent.
The letter writer claimed to have sorted the problem by shouting through his neighbour's letterbox "Alexa !! Turn up the heating"......