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Grant HP290

Lusk, Dublin · Semi-detached · 121 m² · 1983 to 2011 · 9 kW · radiators · installed by Leinster Heatpumps

Last 7 days

168 hourly rows · MID-class heat meter present: no
4.22efficiency (COP) over 168 hours, from the heat meter
better than 88% of the metered fleet in January 2026
Electricity used
80 kWh
Heat delivered
336 kWh (heat meter)
Estimate without heat meter
flow sensor 3.92 · temperature model 5.26
Mean outdoor temperature
10.8 °C · 132 space-heating hours · cooling 1 kWh removed (0 kWh electricity), kept out of the COP
Flow temperature at 0 °C outside
32.3 °C (curve slope -0.21 per K)
Flow − return while heating
2.0 K
House needs at −3 °C
2.1 kW (unit rated 9 kW) · fit r² 0.00
Hot water
23% of electricity, COP 3.27
warningOnly 2 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.
infoUnit is rated 9 kW but the house needs about 2.1 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 day06122026-10-31: 6.1 kWh, outside 12.9 °C2026-11-01: 11 kWh, outside 10.5 °C2026-11-02: 11.8 kWh, outside 9.8 °C2026-11-03: 11.6 kWh, outside 10.9 °C2026-11-04: 10.7 kWh, outside 11.1 °C2026-11-05: 11.9 kWh, outside 10.9 °C2026-11-06: 11.8 kWh, outside 10.6 °C2026-11-07: 4.7 kWh, outside 9.1 °Cdaily COP (heat ÷ electricity)1352026-10-31: COP 4.282026-11-01: COP 3.982026-11-02: COP 4.052026-11-03: COP 4.212026-11-04: COP 4.482026-11-05: COP 4.32026-11-06: COP 4.342026-11-07: COP 3.8610-3111-0111-0211-0311-0411-0511-0611-07
Daily COP needs a heat meter; days without one show electricity only.

The installed heating curve

one heating hourfitted curve50 °C
20304050606789101112131415outdoor 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.