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Stiebel Eltron WPL25-AS

Lichfield, UK · Detached · 202 m² · 1940 to 1982 · 12.5 kW · underfloor · installed by Niche Energy Systems Ltd

Last 30 days

721 hourly rows · MID-class heat meter present: no
22.57efficiency (COP) over 721 hours, from the heat meter
better than 100% of the metered fleet in January 2026
Electricity used
100 kWh
Heat delivered
2257 kWh (heat meter)
Estimate without heat meter
flow sensor 4.62 · temperature model 4.89
Mean outdoor temperature
10.6 °C · 61 space-heating hours
Flow temperature at 0 °C outside
25.6 °C (curve slope 0.74 per K)
Flow − return while heating
5.5 K
House needs at −3 °C
4.1 kW (unit rated 12.5 kW) · fit r² 0.00
Hot water
no hot-water flag in data
infoUnit is rated 12.5 kW but the house needs about 4.1 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.

Day by day

electricity per daydaily COP3.0 floor
electricity, kWh per day09172026-10-08: 9.1 kWh, outside 11.1 °C2026-10-09: 12.1 kWh, outside 13.9 °C2026-10-10: 13.9 kWh, outside 11.2 °C2026-10-11: 17.3 kWh, outside 10.2 °C2026-10-12: 9.5 kWh, outside 13.9 °C2026-10-13: 4.8 kWh, outside 15.1 °C2026-10-14: 1.4 kWh, outside 12.6 °C2026-10-15: 1.4 kWh, outside 15.6 °C2026-10-16: 1.4 kWh, outside 10.9 °C2026-10-17: 1.4 kWh, outside 9 °C2026-10-18: 1.4 kWh, outside 9.7 °C2026-10-19: 1.4 kWh, outside 10.4 °C2026-10-20: 1.4 kWh, outside 11.1 °C2026-10-21: 1.4 kWh, outside 8.8 °C2026-10-22: 1.4 kWh, outside 8.5 °C2026-10-23: 1.4 kWh, outside 8.9 °C2026-10-24: 1.4 kWh, outside 8.7 °C2026-10-25: 1.4 kWh, outside 9.5 °C2026-10-26: 1.4 kWh, outside 10.8 °C2026-10-27: 1.4 kWh, outside 12 °C2026-10-28: 1.4 kWh, outside 10.8 °C2026-10-29: 1.4 kWh, outside 11.6 °C2026-10-30: 1.4 kWh, outside 10.5 °C2026-10-31: 1.4 kWh, outside 9.5 °C2026-11-01: 1.4 kWh, outside 9.3 °C2026-11-02: 1.4 kWh, outside 8.5 °C2026-11-03: 1.4 kWh, outside 8.5 °C2026-11-04: 1.4 kWh, outside 9.6 °C2026-11-05: 1.4 kWh, outside 9 °C2026-11-06: 1.4 kWh, outside 9.6 °C2026-11-07: 0.5 kWh, outside 7.5 °Cdaily COP (heat ÷ electricity)1352026-10-08: COP 5.352026-10-09: COP 3.942026-10-10: COP 4.962026-10-11: COP 4.852026-10-12: COP 4.962026-10-13: COP 8.492026-10-14: COP 39.642026-10-15: COP 22.232026-10-16: COP 49.192026-10-17: COP 60.72026-10-18: COP 61.482026-10-19: COP 55.472026-10-20: COP 51.592026-10-21: COP 65.322026-10-22: COP 67.172026-10-23: COP 69.292026-10-24: COP 70.322026-10-25: COP 65.252026-10-26: COP 55.362026-10-27: COP 44.152026-10-28: COP 48.752026-10-29: COP 46.972026-10-30: COP 54.122026-10-31: COP 55.522026-11-01: COP 64.82026-11-02: COP 67.682026-11-03: COP 69.22026-11-04: COP 63.12026-11-05: COP 63.422026-11-06: COP 65.522026-11-07: COP 72.410-0810-1210-1610-2010-2410-2811-0111-05
Daily COP needs a heat meter; days without one show electricity only.

The installed heating curve

one heating hourfitted curve50 °C
2030405060678910111213141516outdoor 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.