Heatproof
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Vaillant Arotherm+

Rowledge Surrey · Detached · 400 m² · 1983 to 2011 · 10 kW · underfloor

Last 30 days

721 hourly rows · MID-class heat meter present: yes
5.61efficiency (COP) over 721 hours, from the heat meter
better than 99% of the metered fleet in January 2026
Electricity used
247 kWh
Heat delivered
1384 kWh (heat meter)
Estimate without heat meter
flow sensor 5.25 · temperature model 5.34
Mean outdoor temperature
10.8 °C · 184 space-heating hours · cooling 1 kWh removed (0 kWh electricity), kept out of the COP
Flow temperature at 0 °C outside
31.0 °C (curve slope -0.34 per K)
Flow − return while heating
3.1 K
House needs at −3 °C
11.1 kW (unit rated 10 kW) · fit r² 0.12
Hot water
15% of electricity, COP 3.54
infoNo configuration faults detected in this window
Keep the current settings. We will alert you if efficiency drifts.

Day by day

electricity per daydaily COP3.0 floor
electricity, kWh per day011222026-10-08: 0 kWh, outside 11.6 °C2026-10-09: 0 kWh, outside 14.7 °C2026-10-10: 0 kWh, outside 11 °C2026-10-11: 0 kWh, outside 11.3 °C2026-10-12: 1.2 kWh, outside 14.7 °C2026-10-13: 0 kWh, outside 15.9 °C2026-10-14: 2.7 kWh, outside 13.7 °C2026-10-15: 0 kWh, outside 16.7 °C2026-10-16: 1.4 kWh, outside 11.9 °C2026-10-17: 8.2 kWh, outside 8.5 °C2026-10-18: 15.8 kWh, outside 8.4 °C2026-10-19: 5.2 kWh, outside 9.8 °C2026-10-20: 5.1 kWh, outside 10.2 °C2026-10-21: 15.8 kWh, outside 8.8 °C2026-10-22: 7.9 kWh, outside 11.4 °C2026-10-23: 12.9 kWh, outside 9.8 °C2026-10-24: 17.8 kWh, outside 10.4 °C2026-10-25: 7.3 kWh, outside 10.3 °C2026-10-26: 8.7 kWh, outside 12.2 °C2026-10-27: 2.3 kWh, outside 12.9 °C2026-10-28: 12.1 kWh, outside 11.2 °C2026-10-29: 2.1 kWh, outside 11.2 °C2026-10-30: 11.9 kWh, outside 10.2 °C2026-10-31: 10.4 kWh, outside 9.7 °C2026-11-01: 22.3 kWh, outside 7.4 °C2026-11-02: 7.5 kWh, outside 8.6 °C2026-11-03: 16.1 kWh, outside 8.5 °C2026-11-04: 21.1 kWh, outside 8.1 °C2026-11-05: 8.6 kWh, outside 7.7 °C2026-11-06: 17.9 kWh, outside 8.1 °C2026-11-07: 4.6 kWh, outside 4.7 °Cdaily COP (heat ÷ electricity)1352026-10-12: COP 2.552026-10-14: COP 7.42026-10-16: COP 3.322026-10-17: COP 4.842026-10-18: COP 5.172026-10-19: COP 6.332026-10-20: COP 7.32026-10-21: COP 5.282026-10-22: COP 5.562026-10-23: COP 5.332026-10-24: COP 5.652026-10-25: COP 5.612026-10-26: COP 5.692026-10-27: COP 2.952026-10-28: COP 5.612026-10-29: COP 3.022026-10-30: COP 6.232026-10-31: COP 6.412026-11-01: COP 6.012026-11-02: COP 4.912026-11-03: COP 5.572026-11-04: COP 5.522026-11-05: COP 5.952026-11-06: COP 5.892026-11-07: COP 4.9110-0810-1210-1610-2010-2410-2811-0111-05
Daily COP needs a heat meter; days without one show electricity only.

The installed heating curve

one heating hourfitted curve50 °C
20304050603579111315outdoor temperature, °Cflow temperature, °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.