Heatproof
Home / system #53

Vaillant Arotherm+

Stroud, Gloucestershire · Detached · 215 m² · 1940 to 1982 · 5 kW · underfloor · installed by Rickman Renewables

Last 30 days

672 hourly rows · MID-class heat meter present: yes
5.15efficiency (COP) over 672 hours, from the heat meter
better than 99% of the metered fleet in January 2026
Electricity used
227 kWh
Heat delivered
1170 kWh (heat meter)
Estimate without heat meter
flow sensor 5.07 · temperature model 5.42
Mean outdoor temperature
11.4 °C · 474 space-heating hours · cooling 0 kWh removed (0 kWh electricity), kept out of the COP
Flow temperature at 0 °C outside
32.1 °C (curve slope -0.23 per K)
Flow − return while heating
2.5 K
House needs at −3 °C
4.4 kW (unit rated 5 kW) · fit r² 0.19
Hot water
no hot-water flag in data
warningOnly 2.5 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
electricity, kWh per day09172026-10-08: 5.5 kWh, outside 12.7 °C2026-10-09: 3.2 kWh, outside 15.2 °C2026-10-10: 9 kWh, outside 12.1 °C2026-10-11: 7.4 kWh, outside 13 °C2026-10-12: 2.7 kWh, outside 16.4 °C2026-10-13: 2 kWh, outside 16.1 °C2026-10-14: 4.7 kWh, outside 13.8 °C2026-10-15: 0.4 kWh, outside 17.3 °C2026-10-16: 11.5 kWh, outside 12.7 °C2026-10-17: 17.1 kWh, outside 9.3 °C2026-10-18: 16.4 kWh, outside 9.4 °C2026-10-19: 12.5 kWh, outside 10.6 °C2026-10-20: 9.8 kWh, outside 10.1 °C2026-10-21: 11.5 kWh, outside 9.6 °C2026-10-22: 10.5 kWh, outside 10.8 °C2026-10-23: 11.8 kWh, outside 9.7 °C2026-10-24: 9.7 kWh, outside 10.9 °C2026-10-25: 6.1 kWh, outside 10.5 °C2026-10-27: 4.6 kWh, outside 10.8 °C2026-10-28: 6.7 kWh, outside 11.9 °C2026-10-29: 3.1 kWh, outside 12.5 °C2026-10-30: 5.1 kWh, outside 11.3 °C2026-10-31: 5.9 kWh, outside 10.5 °C2026-11-01: 7.1 kWh, outside 9.3 °C2026-11-02: 6.8 kWh, outside 8.9 °C2026-11-03: 8.7 kWh, outside 8.5 °C2026-11-04: 7.9 kWh, outside 9.6 °C2026-11-05: 8.5 kWh, outside 9.2 °C2026-11-06: 7.7 kWh, outside 9.8 °C2026-11-07: 3.2 kWh, outside 8.6 °Cdaily COP (heat ÷ electricity)1352026-10-08: COP 5.192026-10-09: COP 5.142026-10-10: COP 5.332026-10-11: COP 5.242026-10-12: COP 4.862026-10-13: COP 4.962026-10-14: COP 5.122026-10-16: COP 5.242026-10-17: COP 4.722026-10-18: COP 4.82026-10-19: COP 5.232026-10-20: COP 5.232026-10-21: COP 5.212026-10-22: COP 5.282026-10-23: COP 5.132026-10-24: COP 5.132026-10-25: COP 5.32026-10-27: COP 5.092026-10-28: COP 5.262026-10-29: COP 5.452026-10-30: COP 5.492026-10-31: COP 5.442026-11-01: COP 5.192026-11-02: COP 4.932026-11-03: COP 5.192026-11-04: COP 5.312026-11-05: COP 5.282026-11-06: COP 5.422026-11-07: COP 5.2310-0810-1210-1610-2010-2410-2911-0211-06
Daily COP needs a heat meter; days without one show electricity only.

The installed heating curve

one heating hourfitted curve50 °C
20304050605678910111213141516outdoor 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.