Heat pump standby power consumption, Digi Mart USA News: A heat pump that is not producing heat still draws electricity for its circulation pumps, electronic boards and the crankcase heater that keeps the compressor oil warm. According to measurements from the French environment and energy agency ADEME, the average standby draw is 24 W, or about 96 kWh per year outside the heating season, but the most power-hungry unit draws up to 198 W, or nearly 800 kWh over a year.
This consumption neither heats the house nor the water. The source reports that three adjustments made by manufacturers reduced standby consumption, and households are advised to ask their installer about them.
The ADEME observatory, which extends a measurement campaign covering 100 heat pumps, recorded an average of 24 W when no heat was being produced, with variations from 0 W to 198 W depending on the home. The measurements cover about 80 individual houses during summer, when the units were not heating.
Reversible air-to-air air conditioners were not part of the sample.
Based on a cost estimate using the regulated electricity tariff, the standby draw costs about 19 euros per year on average, rising to 40 euros at 50 W and about 158 euros at 198 W. These estimates use the Base option of the regulated sales tariff at 0.2001 euros per kWh including tax for 3 and 6 kVA subscriptions, as of August 1, 2026, and are approximations.
Two-thirds of the pumps measured draw more than 10 W when idle, and 14 percent exceed 50 W. The report does not name the manufacturers whose units account for the highest readings.
Roughly one in three pumps stays below 10 W, and a little over half fall between 10 W and 50 W.
When a single pump from one manufacturer shows high standby consumption, the report points to a commissioning problem, such as a circulator or heater running continuously. When most pumps from the same manufacturer are affected, the report does not rule out a cause specific to the equipment, such as standby draw from the electronic board or faulty crankcase heater control.
Three adjustments reduced standby consumption in homes where manufacturers intervened: a software update for the outdoor and indoor unit control boards, switching the circulators to eco mode, and enabling control of the crankcase heater. In these homes, average standby consumption fell by a factor of 2.4 over one year.
The report suspects that crankcase heater control is the adjustment with the greatest effect.
The overall results are more modest. Standby consumption rose elsewhere, from 13.6 W to 73.3 W in one case and from 90 W to 198 W in another, where the manufacturer also found a refrigerant leak.
Across the sample, the average decrease was only 13 percent, from 27.5 W to 24 W.
Other settings have a larger effect than standby power. The heating curve, which sets the temperature of water sent to radiators, saved up to 2,000 kWh per year in one home in the observatory, and running a wood stove can reduce the heat pump’s efficiency.
The report considers it advisable to switch off a heat pump used only for space heating, without hot water, outside the heating season when its standby draw exceeds 10 W, reconnecting it monthly so the circulators do not seize. Four participants in the observatory tried this without any malfunction.
Some manufacturers are reluctant to recommend this because of the risk of circulator seizing, and the off button does not always eliminate board standby draw, and some models lack one.
Heating will be needed again from Saturday, November 14, with forecast minimum temperatures of -1.4 °C in Clermont-Ferrand and -1 °C in Nancy on Sunday, according to forecasts issued November 9.
Homeowners are advised to ask their installer during the next maintenance visit to measure the pump’s power draw when it is not heating, and to check three points: the control board software, the circulator eco mode, and crankcase heater control. For a pump used only for heating, the question of a summer shutdown is worth raising before next summer.
