721 hourly rows · MID-class heat meter present: yes
2.94efficiency (COP) over 721 hours, from the heat meter better than 7% of the metered fleet in January 2026
Electricity used
1079 kWh
Heat delivered
3167 kWh (heat meter)
Estimate without heat meter
flow sensor 2.73 · temperature model 3.27
Mean outdoor temperature
5.3 °C · 467 space-heating hours · cooling 8 kWh removed (4 kWh electricity), kept out of the COP
Flow temperature at 0 °C outside
39.6 °C (curve slope -0.31 per K)
Flow − return while heating
4.5 K
House needs at −3 °C
7.8 kW (unit rated 16 kW) · fit r² 0.12
Hot water
14% of electricity, COP 2.35
seriousWinter efficiency 2.94 is below the 3.0 floor used for German subsidies
Ask the installer for a commissioning check; the causes are usually flow temperature, hot water settings, or sizing, all listed below.
infoUnit is rated 16 kW but the house needs about 7.8 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.
valueReaching the fleet’s January median (3.69) would have saved about £55 in this window at 0.25 GBP/kWh. An estimate, not a promise.
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.