Heatproof
Home / system #421

Daikin Altherma 2

Horsham, West Sussex · Detached · 128 m² · 1983 to 2011 · 7 kW · radiators · installed by Octopus Energy Services

Last 7 days

168 hourly rows · MID-class heat meter present: no
3.76efficiency (COP) over 168 hours, from the heat meter
better than 59% of the metered fleet in January 2026
Electricity used
92 kWh
Heat delivered
345 kWh (heat meter)
Estimate without heat meter
flow sensor 3.81 · temperature model 4.05
Mean outdoor temperature
9.4 °C · 132 space-heating hours
Flow temperature at 0 °C outside
38.1 °C (curve slope -0.39 per K)
Flow − return while heating
3.5 K
House needs at −3 °C
3.8 kW (unit rated 7 kW) · fit r² 0.16
Hot water
12% of electricity, COP 2.61
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 day08162026-10-31: 4.3 kWh, outside 14.8 °C2026-11-01: 12.7 kWh, outside 9.2 °C2026-11-02: 11.4 kWh, outside 10 °C2026-11-03: 11.7 kWh, outside 10.1 °C2026-11-04: 16.1 kWh, outside 8.4 °C2026-11-05: 12.3 kWh, outside 9.3 °C2026-11-06: 12.7 kWh, outside 8.2 °C2026-11-07: 10.7 kWh, outside 3.3 °Cdaily COP (heat ÷ electricity)1352026-10-31: COP 4.032026-11-01: COP 4.042026-11-02: COP 3.932026-11-03: COP 3.872026-11-04: COP 3.742026-11-05: COP 3.892026-11-06: COP 3.992026-11-07: COP 2.5810-3111-0111-0211-0311-0411-0511-0611-07
Daily COP needs a heat meter; days without one show electricity only.

The installed heating curve

one heating hourfitted curve50 °C
203040506002468101214outdoor 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.