Late to the party, but I’m curious whether your quarterly usage has gone down since that first shock bill. A ground-source heat pump should run more efficiently once the system settles and you tweak the settings. Did you ever check the installer’s configuration or the circulation pump timings? If anyone else with a similar setup is still reading, what are your yearly kWh figures for a 4-bedroom house?
I put a power meter on the heatpump last year. Can’t seem to bring up the full year stats, but it’s been about 400kWh for the last 30 days (house of 200m2). I think it was higher last year but I accidentally factory reset the pump…somehow I think my own settings are using less than those put in at the comissioning (new heatpump installed early 2024).
All will depend how warm you like it.
We heat to 23° all winter - Full details in my May 2025 post above. Air heat pump for heating and separate air heat pump unit for hot water installed June 2025 replacing previous 18-year old heat pump.
I can tell you I estimated our use in 2018 at approx 9600kWh per year. We run 2 low-mileage EVs. Since 2020 we have 9.6kWhp PV panels. We used 8006kWh in 2025. The reality is complicated. Anyway, our total bill for electricity in 2025 now in at CHF1443