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Samsung Gen 6

Carlby, STAMFORD · Detached · 184 m² · 1940 to 1982 · 12 kW · radiators · installed by Forerunner (Electronic) Ltd

Last 30 days Last 7 days 5 Jan – 4 Feb 2026 (winter reference)1–31 Dec 2025

Last 7 days

169 hourly rows · MID-class heat meter present: no

2.86efficiency (COP) over 169 hours, from the heat meter
better than 6% of the metered fleet in January 2026

Electricity used: 107 kWh
Heat delivered: 306 kWh (heat meter)
Estimate without heat meter: flow sensor 2.80 · temperature model 3.35
Mean outdoor temperature: 8.9 °C · 75 space-heating hours
Flow temperature at 0 °C outside: 35.8 °C (curve slope 0.61 per K)
Flow − return while heating: 3.6 K
House needs at −3 °C: 2.4 kW (unit rated 12 kW) · fit r² 0.01
Hot water: no hot-water flag in data

seriousWinter efficiency 2.86 is below the 3.0 floor used for German subsidies

Ask the installer for a commissioning check; the causes are usually flow temperature, hot water settings, or sizing, all listed below.

infoUnit is rated 12 kW but the house needs about 2.4 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.

noteOwner’s note on the source site: “Outside temperature error”

valueReaching the fleet’s January median (3.69) would have saved about £6 in this window at 0.25 GBP/kWh. An estimate, not a promise.

Day by day

electricity per daydaily COP3.0 floor

Daily COP needs a heat meter; days without one show electricity only.

The installed heating curve

one heating hourfitted curve50 °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.