Home / system #1409
Vaillant Arotherm+ V2
Acton, London · Semi-detached · 128 m² · 1900 to 1939 · 5 kW · radiators · installed by Dwellow
Last 7 days
169 hourly rows · MID-class heat meter present: no
5.03efficiency (COP) over 169 hours, from the heat meter
better than 99% of the metered fleet in January 2026
better than 99% of the metered fleet in January 2026
- Electricity used
- 66 kWh
- Heat delivered
- 334 kWh (heat meter)
- Estimate without heat meter
- flow sensor 4.38 · temperature model 4.52
- Mean outdoor temperature
- 10.1 °C · 145 space-heating hours
- Flow temperature at 0 °C outside
- 36.9 °C (curve slope -0.44 per K)
- Flow − return while heating
- 1.6 K
- House needs at −3 °C
- 3.1 kW (unit rated 5 kW) · fit r² 0.09
- Hot water
- 19% of electricity, COP 4.45
warningOnly 1.6 K between flow and return
Circulation pump may be set too high or emitters are undersized for the low flow temperature. Ask the installer to check pump speed.
Day by day
electricity per daydaily COP3.0 floor
The installed heating curve
one heating hourfitted curve50 °C
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.