Heatproof
Deutsch
Sprache
DeutschEnglish
Darstellung
DunkelHellSystem
Ansicht
Einfach: nur der Rechnungs-CheckVollständig: alle Seiten
Home / system #889

Vaillant Arotherm+

Andover, Hampshire · Semi-detached · 143.5 m² · 1940 to 1982 · 7 kW · underfloor · installed by Hurfords Heating

Last 30 daysLast 7 days5 Jan – 4 Feb 2026 (winter reference)1–31 Dec 2025

Last 30 days

721 hourly rows · MID-class heat meter present: yes
6.68efficiency (COP) over 721 hours, from the heat meter
better than 100% of the metered fleet in January 2026
Electricity used
170 kWh
Heat delivered
1136 kWh (heat meter)
Estimate without heat meter
flow sensor 6.73 · temperature model 4.89
Mean outdoor temperature
10.8 °C · 231 space-heating hours · cooling 0 kWh removed (0 kWh electricity), kept out of the COP
Flow temperature at 0 °C outside
27.2 °C (curve slope -0.01 per K)
Flow − return while heating
2.1 K
House needs at −3 °C
4.2 kW (unit rated 7 kW) · fit r² 0.00
Hot water
31% of electricity, COP 4.63
warningOnly 2.1 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.
warningHot water uses 31% of electricity at COP 4.63
Lower the tank target to 45–48 °C, heat water once a day in the warmest hours, and disable weekly legionella cycles unless required.

Day by day

electricity per daydaily COP3.0 floor
electricity, kWh per day05102026-10-08: 1.1 kWh, outside 11.8 °C2026-10-09: 2.2 kWh, outside 14.3 °C2026-10-10: 3.6 kWh, outside 11.2 °C2026-10-11: 5.1 kWh, outside 11.9 °C2026-10-12: 1.6 kWh, outside 15.3 °C2026-10-13: 1.9 kWh, outside 15.7 °C2026-10-14: 4.4 kWh, outside 12.8 °C2026-10-15: 1.7 kWh, outside 16.1 °C2026-10-16: 1.7 kWh, outside 11.9 °C2026-10-17: 6.8 kWh, outside 8.6 °C2026-10-18: 5.2 kWh, outside 9.1 °C2026-10-19: 4.4 kWh, outside 9.7 °C2026-10-20: 1.9 kWh, outside 9.4 °C2026-10-21: 8.7 kWh, outside 9.5 °C2026-10-22: 4.4 kWh, outside 11.1 °C2026-10-23: 7.5 kWh, outside 9.7 °C2026-10-24: 6.2 kWh, outside 10.4 °C2026-10-25: 5.7 kWh, outside 10.4 °C2026-10-26: 4.5 kWh, outside 12.2 °C2026-10-27: 4.2 kWh, outside 12.8 °C2026-10-28: 6.2 kWh, outside 11.1 °C2026-10-29: 6.5 kWh, outside 11.4 °C2026-10-30: 6.8 kWh, outside 10.2 °C2026-10-31: 7.4 kWh, outside 9.4 °C2026-11-01: 10.4 kWh, outside 7.1 °C2026-11-02: 8.9 kWh, outside 8.8 °C2026-11-03: 10.4 kWh, outside 8.4 °C2026-11-04: 10.2 kWh, outside 8.2 °C2026-11-05: 10 kWh, outside 7.6 °C2026-11-06: 6.1 kWh, outside 8.6 °C2026-11-07: 4.6 kWh, outside 7 °Cdaily COP (heat ÷ electricity)1352026-10-08: COP 5.392026-10-09: COP 3.392026-10-10: COP 5.552026-10-11: COP 4.592026-10-12: COP 2.832026-10-13: COP 3.92026-10-14: COP 4.452026-10-15: COP 3.322026-10-16: COP 3.362026-10-17: COP 4.742026-10-18: COP 4.882026-10-19: COP 4.972026-10-20: COP 3.592026-10-21: COP 5.272026-10-22: COP 4.962026-10-23: COP 7.992026-10-24: COP 7.742026-10-25: COP 7.792026-10-26: COP 7.312026-10-27: COP 7.42026-10-28: COP 7.482026-10-29: COP 7.812026-10-30: COP 7.682026-10-31: COP 7.672026-11-01: COP 7.782026-11-02: COP 7.822026-11-03: COP 7.772026-11-04: COP 7.552026-11-05: COP 7.692026-11-06: COP 7.22026-11-07: COP 6.7210-0810-1210-1610-2010-2410-2811-0111-05
Daily COP needs a heat meter; days without one show electricity only.

The installed heating curve

one heating hourfitted curve50 °C
20304050604567891011121314outdoor 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.