Melcloud vs measured Shelly values


Anyone else noted that Melcloud values seems to be very slightly off on air to air heat pump?
Shelly shows 4.63kWh
Air heat pump shows 5.1kWh

Shelly shows 20.38kWh
Air heat pump shows 21.8kWh

In real life this doesn’t matter in any way, but just posting this for devs in case there is some small offset on their calculations as I understood these bit weird values that melcloud gives.

I’ve just started doing this because I was getting significant errors between MELCloud & my (MID certified) consumer panel energy meter. Comparing (now) 3 sets of readings I’ve concluded there are 2 issues:-

  • MELCloud does not always incude the energy supplied to the pumps, eg when the frost stat is running
  • Shelly EM isn’t perfectly accurate, it is often around 5% in error cf the panel meter. I’ve now tried 4 different CTs and they all show varying errors when compared to the panel meter and each other.

If my ecodan is only running the pumps when the unit is heating then its energy reading is closer to the MID panel meter than the Shelly CTs are.