I’m doing something similar by monitoring HeatPumpFrequency from MELCloud; if that becomes zero while I expect the heating to be on, then I’ll drop the target flow temperature by 7 degrees. When the flow temperature drops to that new target, I restore it back up to what it should be which triggers the next heating cycle. This typically results in around 15 minutes of idle time between cycles, and possibly improve CoP a little too.
Power consumption remains about 120 or 180 W as the circulation pumps keep running.
John suggested doing the same in hardware: Someone needs to make a relay module
The electric meter is sending 1 pulse per Wh, and the FTC can only report whole numbers of energy consumption (not instantaneous power). 1Wh = 60W for 1 minute. As a result, you’ll see if flip between 0 and 60W when idle. For my system, this averages out to 20W.