Is Your Heat Pump Working Right? Free Performance Check
Enter before-and-after monthly kWh and the month’s weather to see whether your heat pump’s real draw sits inside its NEEP-rated envelope.
· Source: EIA Electric Power Monthly Table 5.6.A (July 2026 data) · next EIA update ~Oct 23
On this page: CalculatorTableHow we calculatedSources
Jump to calculator ↓Defaults from regional degree-days; drag if you know your month ran colder or milder. The URL keeps your scenario.
Physics of the test: at the rated point, electrical draw = capacity ÷ COP ÷ 3,412 kW; running flat-out for the whole month is the hard ceiling for compressor-only consumption. Ratings: NEEP ccASHP database (retrieved 2026-09-10, table below). Default mean temp = 65°F − HDD/day, EIA STEO regional HDD. This is triage, not diagnosis — short cycling, duct losses and backup-strip runtime are for a technician with instruments.
- Inputs needed
- Monthly kWh before install, kWh after, rough outdoor conditions
- Comparison basis
- NEEP-rated envelope of the named unit or median curve
- Two possible reads
- Within the rated envelope, or worth investigating
- What it can't do
- Diagnose short cycling, duct losses, or backup-strip runtime
- What confirms a problem
- A technician's on-site check, not a kWh comparison
- Best used for
- Deciding whether a service call is worth making
Why this number
A new heat pump changes the electric bill by definition — the question is whether it changed it the way its own rating sheet says it should. This check answers that with physics, not vibes.
Rated electrical draw of the listed units
| Unit | 47°F kW | 17°F kW | 5°F kW |
|---|---|---|---|
| Mitsubishi Electric MUZ-GS24NAHZ*** | 4.05 | 3.35 | 3.19 |
| Mitsubishi Electric PUZ-HA30NKA | 3.03 | 4.44 | 4.86 |
| Fujitsu AOU24RLXFWH | 3.38 | 3.59 | 3.35 |
| Daikin DZ6VSA361EA* | 2.93 | 4.82 | 4.40 |
| LG KUSXB301A | 4.00 | 4.10 | 4.41 |
| Bosch BMS500-AAS024-1CSXRC | 2.66 | 2.75 | 2.55 |
| Trane 4TXD2060A10NU** | 4.14 | 6.90 | 6.35 |
Derived from each unit's NEEP-listed max-speed capacity and COP (kW = BTU/hr ÷ COP ÷ 3,412); the underlying ratings and listing links are on the crossover page.
A heat pump install either performs the way its rating suggests it should, or it doesn’t — and the only evidence most homeowners have is a monthly electric bill. This tool turns your before/after kWh and rough outdoor conditions into an implied performance figure and checks it against the NEEP-rated envelope of the closest named unit, rather than asking you to judge a raw number in isolation.
What this check can tell you — and what it can’t
Within the envelope means your numbers are consistent with how NEEP-listed cold-climate units are expected to perform under those outdoor conditions — a reasonable sign the system is doing what it was rated to do. Outside the envelope means the gap is large enough to be worth a closer look, not a confirmed problem: this tool has no way to see inside the ductwork, read a refrigerant charge, or watch how often the compressor cycles or the backup strips fire. Short cycling, duct losses, and backup-strip runtime are the most common real causes of a worse-than-expected result, and every one of them requires a technician with equipment access and a meter to confirm — not a monthly kWh comparison. This tool triages; it does not diagnose. Its job is deciding whether a service call is worth making, and giving you a specific, named reason to bring to that call rather than a vague complaint about the bill.
Next steps
If the concern started with the bill itself rather than the heat pump specifically, why is my electric bill so high splits an increase into weather, rate, and usage first. To check whether the install should be saving money at your actual rates before assuming performance is the issue, use the heat pump vs furnace cost calculator . And for what normal heat pump wattage and runtime should cost on their own, see cost to run: heat pump .
Frequently asked questions
My usage went up after installing a heat pump — what happened?
That alone doesn’t mean something’s wrong. A heat pump often replaces a fuel other than electricity for heating, so total electric usage rising while your gas or oil usage drops (or disappears) can be exactly what a successful install looks like. This tool weighs your after-install usage against outdoor conditions and the unit’s rated envelope rather than against your old bill in isolation, because the old bill was heating a different way.
Is the rated COP realistic at my actual temperatures?
NEEP-rated figures come from standardized lab test points, and real installed performance is shaped by ductwork, install quality, altitude, and how well the equipment matches the listed model — so some gap between rated and real-world performance is normal, not a defect. That’s why this tool checks whether your implied performance falls inside the envelope across listed units rather than against one exact number; a result well outside that spread is the signal worth following up on, not a small gap from it.
How much do backup strips distort this comparison?
A lot, if they’re running more than intended. Electric resistance backup uses far more electricity per unit of heat than the compressor does, so a system leaning on backup strips during cold snaps, short cycling, or a stuck defrost cycle can push monthly kWh well above what the heat pump’s own rated performance would predict — without the compressor itself being at fault. This tool can flag that the numbers look off; only a technician checking the controls and runtime logs can confirm backup-strip behavior is the cause.
When should I call the installer instead of trusting this tool?
As soon as this tool says your implied performance is worth investigating, or if you notice the system short cycling, uneven room temperatures, unusual noise, or ice buildup that doesn’t clear in defrost. Those are technician-diagnosis situations — duct static pressure, refrigerant charge, control settings — that a monthly kWh comparison was never built to resolve; this tool’s job is telling you the call is likely worth making, not making it for you.
How we calculated this
Implied draw (kW) = extra kWh ÷ hours in the month; the rated envelope is capacity (Btu/h) ÷ COP ÷ 3,412 at the NEEP 47/17/5°F points of the chosen unit, interpolated to your month’s mean temperature. Inside the envelope = consistent with the rating; above it = investigate (auxiliary strips, duct loss, setpoint).Sources: U.S. Energy Information Administration (EIA) electricity rates · DSIRE incentive records · public IRS/OBBBA guidance. Figures are modeled estimates, not quotes or tax advice. See our methodology.
Where to go next
- Oil vs heat pump cost — If the unit is performing to its envelope, this is what it should be saving against oil at your state’s prices.
- Why is my electric bill so high? — Split any bill increase into weather, rate, and usage before assuming the heat pump is the cause.
- Heat pump vs furnace cost calculator — Check whether the install should be saving money at your rates in the first place.
- Cost to run: heat pump — See what a heat pump’s wattage and runtime should cost under normal operation, for comparison.