What people actually pay to heat with a heat pump

Why I built this

The most common question about heat pumps is some version of "is my bill normal?", and the honest answer available anywhere on the internet is a range so wide it is useless. Fifty to a hundred and fifty dollars a month. Somewhere between fine and catastrophic.

Federal field studies exist and this site leans on them heavily, but they measure a couple of dozen instrumented houses under research conditions. [PNNL-37127 (2025)] [NREL/TP-5500-84745 (2023)] What they cannot tell you is what ordinary people with ordinary installations are actually seeing on ordinary bills.

People do publish that, in public discussion, constantly. It is just never collected, never normalised, and therefore never comparable. A figure of 2,300 kWh means nothing without the floor area, and floor area means nothing without the climate. So I collected the reports that carried enough context, converted them onto one scale, and put a data quality tier on every row so you can see how much weight each one carries.

How these are made comparable

Three things vary between households and all three have to come out before any comparison means anything.

1. House size. Divide by conditioned floor area.
2. Climate. Divide by heating degree days for the month in question. Where a householder stated their own degree day figure I used theirs. Otherwise I applied the EIA ten year normal for their census division, scaled to the month. [EIA STEO degree days]
3. What is being measured. Some reports isolate the heat pump circuit. Most are whole house electricity, which includes lighting, appliances and hot water. That difference is marked on every row and it is the main reason not to read too much into small gaps.

What comes out is watt hours per square foot per heating degree day. It is not a standard industry metric and I am not proposing it as one. It is simply the smallest set of divisions that lets two houses in two climates be put next to each other.

The households

Sorted best to worst. All figures self-reported by the householder in public discussion. Where a household reported a range, the single month named is used.

What a household with nothing wrong with it uses

A draft of this page drew the band statistically, by cutting the sorted list where the largest ratio gaps fell. It never went live. It held at eighteen households and broke at twenty one, because the next batch landed squarely in the gap it relied on and the band widened from 1.6 times to 2.8. The distribution has no natural seam in it, so any rule that depends on finding one will keep moving.

What the data does divide on is whether anybody found anything. 8 of these 21 households have a specific identified problem, named in the section below, found either by the householder or from their own posted numbers. The other 13 have no fault anybody has identified.

Those 13 run from 0.21 to 0.92 watt hours per square foot per heating degree day. Take out the single exceptional building at the bottom, an Indiana house discussed below whose figure is a fifth of everyone else's, and the remaining 12 sit between 0.53 and 0.92, a spread of 1.7 times across houses from 1,100 to 3,800 square feet in four census divisions on equipment from at least six manufacturers.

Two honest warnings about that band. It is drawn from people who chose to post their numbers, a group weighted toward the alarmed, so the middle of this sample is not the middle of American heat pump installations. And a household with no identified fault is not the same as a household with no fault; it means nobody looked, or nobody found anything.

The households with something wrong, and what it was

This is the result that makes the collection worth continuing. Every one of the 8 households above the band has a specific cause, and in every case it is a setting, a habit, a breaker or a second heating system. Not one is there because of the weather or the badge on the outdoor unit.

Read that last column before the third one. 5 of these 8 were found by the householder, who could go and look at the machine. 3 are my reading of numbers posted in a thread, without access to the house, and those are the ones to trust least. One of them I have already got wrong once and corrected in public.

What to do if you are up here

Grouped by what the causes above have in common, cheapest first. Nothing in this list needs a technician until the last item.

• Find out whether a second heating system is running. Three of the 8 come down to electric resistance heat operating alongside the heat pump: baseboards left live in Connecticut and in midcoast Maine, and strips taking the whole load in Ohio because a breaker was off. Resistance heat delivers at a coefficient of performance of exactly 1.0 whatever the heat pump is doing. Walk the house and read every thermostat and every breaker.
• Check what your thermostat calls backup heat for. If it stages in resistance whenever the room is more than 2F below setpoint, every recovery from a setback is being run at a coefficient of performance of 1.0. The arithmetic on that comes to roughly 200 kWh a month on an average house.
• Find the compressor lockout in the installer menu. A factory default near 35F on a modern unit hands the load to the strips for most of the winter. This is the single most likely explanation for the New Hampshire household, and the test takes two numbers off your bill.
• Subtract what is not heating before you panic. The Massachusetts household above is only up here because an electric vehicle charges on the same meter. A shoulder month subtraction would have shown that in a minute.
• Then call somebody. Refrigerant charge, airflow and a blower door test all cost money, and all of them are worth doing after the free checks rather than instead of them.

The two ends, side by side

The degree day figures differ by less than two percent. These are the same winter, thermally. One household uses 12 times more electricity per square foot to deal with it.

Why Indiana is so low

R-83 in the attic against a code minimum nearer R-38. Ducts and air handler inside the conditioned envelope rather than in a vented crawlspace or attic. A bi-level with the lower floor half below grade, which the owner estimates halves the load on that half of the house. Simple rectangular plan, eight foot ceilings, no dormers. The owner also runs no night setback and reports a balance point near 1F, so the resistance strips essentially never engage.

Nothing in that list is the heat pump. It is a 2-ton unit that is not even a cold climate model. The full write-up is in the fieldwork note, including the correction where I first published that this household's figures were impossible.

Why coastal Maine is so high

Two ductless units whose combined maximum electrical draw, run flat out without stopping for every hour of the month, still cannot account for the bill. Something in that house is making heat at a coefficient of performance near 1.0, and the likeliest candidate is the electric baseboards the heat pumps were supposed to replace, taking over every day the owner switches the heat pumps off. The full working, both routes to it, and the order to check things in are in the worked case.

And the most expensive system in the set

A $24,000 Samsung installation in New Hampshire with R-60 in the attic, returning an implied seasonal COP between 1.24 and 1.42 when a working unit returns 2.5 to 3.2. Between half and two thirds of its heat is coming from resistance strips. The likeliest cause is a compressor lockout left at a factory default, which stops the heat pump running below about 35F and hands the load to the strips. The diagnosis, and a calculator to run the same test on your own bill, is on the lockout page.

Two houses measured before and after, which is the only clean test here

Everything above compares different houses. Two households in this collection did something better and reported the same month in consecutive years, with only the heating system changed. That removes the building, the occupants and the habits from the comparison, and leaves the weather.

The first is the site's central claim tested in one building. If the old system was electric resistance, running at a coefficient of performance of exactly 1.0, then delivering the same heat for 2,200 kWh instead of 4,000 implies a seasonal coefficient of performance of 1.82. That is a real gain and it is well short of the 2.5 to 3 the equipment is rated for, which is roughly what the rest of this dataset would lead you to expect from a working but unoptimised installation.

If you are about to have a heat pump fitted, take the reading. A photograph of your meter and a note of the month is free, takes ten seconds, and turns your next winter from an argument into a measurement. Almost nobody in any of these threads had one, and it is the single reason so many of them cannot tell whether their system is working.

Three smaller things the set shows

Utility choice moves the bill as much as the house does

Two southern New Hampshire households appear here. One is served by a municipal cooperative and reports $272 for a month of heat pump operation. The other is on an investor owned utility. Elsewhere in the same discussions, an Indiana homeowner paying $0.193 per kWh notes that residents ten miles south in Kentucky pay $0.097 on the same grid, because one utility is municipal and the other is not.

Every state page on this site quotes a state average and warns that averages hide variation. This is what that warning means.

Heat pump tariffs are real money and are not in any state average

The Massachusetts household reports being on a dedicated heat pump rate at around $0.25 per kWh against a standard rate nearer $0.35. That is a 29% reduction available for a phone call, and it does not appear in the EIA state average this site is built on.

Supplementary heat quietly rewrites several of these rows

At least four households burn wood, pellets or propane alongside the heat pump. Their electricity figures look good and understate their real heating load by an unknown amount. I have flagged each one rather than dropping them, because the honest version of this table includes the rows that need an asterisk.

How this was checked

Every figure in the dataset was published by the householder. I have not adjusted any of them, and where a number was missing I have left the cell empty rather than filling it in.

The normalisation is computed in code from the dataset, not typed in, so the table, the chart and the numbers quoted in the text cannot drift apart. Degree days use each householder's own figure where they gave one, and otherwise the EIA ten year normal for their census division scaled to the month, which is an approximation and is the largest source of error in the comparison.

I checked the tightness of the middle band before trusting the metric. If the normalisation were meaningless, houses this different would not land within 4.4 times of each other across three regions and five manufacturers.

Every household above the band was investigated separately before being included, and in one case I published a wrong conclusion first and corrected it. That is in the corrections log.

What this page does not cover

This is not a study. It is 21 self-selected reports from people who chose to post their numbers publicly, which is a population biased toward the engaged, the pleased and the alarmed. There is no reason to think it represents American heat pump installations generally.

Several households burn wood, pellets or propane alongside the heat pump, which makes their electricity figures look better than their true heating load. Whole house rows include hot water, appliances and lighting, which inflates them by an unknown amount in the other direction.

None of this covers equipment cost, installation quality directly, comfort, or emissions.

References

1. Homeowner report and follow-up discussion, r/heatpumps, January 2026. Southwest Indiana, 2,160 sq ft bi-level, 2-ton Daikin Fit ducted air source heat pump. Figures for design load, capacity, balance point, insulation levels and metered usage are the homeowner's own, given across the thread.
2. Homeowner report and follow-up discussion, r/heatpumps, February 2026. Southern New Hampshire, 1,400 sq ft ranch, Samsung R32 ducted two zone system. Twelve months of utility kWh readings, equipment details and thermostat setpoints are the homeowner's own, posted publicly in the thread.
3. U.S. Energy Information Administration. Short-Term Energy Outlook, heating degree days by census division, prior ten year average series. Accessed through the EIA Open Data API v2.
4. Mendon, V., Keene, K., Rosenberg, S., Rotondo, J. A., Nwe, K., Young, J., Wind, W., and Goetzler, B. (2025). Performance Results from DOE Cold Climate Heat Pump Challenge Field Validation. PNNL-37127. Pacific Northwest National Laboratory, prepared for the U.S. Department of Energy under Contract DE-AC05-76RL01830. January 2025.
5. Winkler, J. and Ramaraj, S. (2023). Field Validation of Air-Source Heat Pumps for Cold Climates. NREL/TP-5500-84745. National Renewable Energy Laboratory. May 2023.