[eek2121]

Unsure if what you posted is true because I don’t know about water based systems, however this has been proven false for heat pumps.

Specifically, setting a fixed temp vs turning things up/down/off when you are leaving and reversing it before you get home. There was little difference either way. The amount of electricity consumed was similar to both.

I wish I had a link, they even tested cases where efficiency was lost heating things up. This includes “emergency heating”.