663 hourly rows · MID-class heat meter present: yes
4.27efficiency (COP) over 663 hours, from the heat meter better than 90% of the metered fleet in January 2026
Electricity used
481 kWh
Heat delivered
2055 kWh (heat meter)
Estimate without heat meter
flow sensor 2.58 · temperature model 4.22
Mean outdoor temperature
9.7 °C · 362 space-heating hours · cooling 0 kWh removed (0 kWh electricity), kept out of the COP
Flow temperature at 0 °C outside
42.3 °C (curve slope -0.40 per K)
Flow − return while heating
5.6 K
House needs at −3 °C
5.0 kW (unit rated 12 kW) · fit r² 0.04
Hot water
57% of electricity, COP 3.31
warningHot water uses 57% of electricity at COP 3.31
Lower the tank target to 45–48 °C, heat water once a day in the warmest hours, and disable weekly legionella cycles unless required.
infoUnit is rated 12 kW but the house needs about 5 kW at −3 °C
Oversizing causes cycling in mild weather. Cannot be fixed cheaply now, but the curve and minimum run time can limit the damage.
noteOwner’s note on the source site: “0W standby power review required”
Day by day
electricity per daydaily COP3.0 floor
Daily COP needs a heat meter; days without one show electricity only.
The installed heating curve
one heating hourfitted curve50 °C
Each point is one hour of space heating. Lower and flatter is cheaper; well-set radiator systems sit around 35–42 °C at 0 °C outside.
Public system published by its owner on HeatpumpMonitor.org. Cycling (starts per hour) comes from the site’s 365-day statistic. Findings use installer rules of thumb; see methodology.