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Short answer: for a heat pump, get the ecobee Smart Thermostat Premium. It exposes the AUX-heat lockout and staging-delta settings numerically, and those two numbers are what actually decide your winter electric bill. No C wire? Get the Nest Learning 4th gen. Tight budget? The Honeywell T6 Pro.
Most smart thermostats will wire to a heat pump and control it. The O/B terminal is standard. The question isn’t compatibility; it’s control. Specifically: does the thermostat let you set an outdoor temperature lockout for aux heat, and does it let you adjust the staging delta?
Those two settings determine whether your heat pump runs efficiently or whether the backup electric strips fire more than they should.
Quick comparison
| Thermostat | Best for | Works with | C-wire | Heat-pump staging | AUX lockout control |
|---|---|---|---|---|---|
| ecobee Premium | Overall efficiency | Alexa, Google, HomeKit, Matter | C-wire or PEK | Up to 4H/2C | Numeric, full |
| Nest Learning 4th | No C-wire + learning | Google, Alexa | Not required | 3H/2C | Heat Pump Balance |
| Honeywell T10 Pro | Pro installs | Alexa, Google | Required | 3H/2C | ISU + wired sensor |
| Sensi Touch 2 | Value, HomeKit | Alexa, Google, HomeKit | Required | 2H/2C | Basic |
| Honeywell T6 Pro | Budget | Alexa, Google | Required | 2H/1C | Basic |
The 3 settings that separate good heat pump thermostats from the rest
1. AUX heat lockout temperature. Below a certain outdoor temp, it’s more efficient to let the strips handle heating alone. Above that temp, running the compressor with minimal AUX is cheaper. A good thermostat lets you set where that crossover happens. Budget thermostats don’t.
2. Staging delta (how far behind before AUX fires). When the room is 2°F below setpoint, should AUX stage up? 5°F? Most factory defaults are conservative (2-3°F), which means strips fire frequently on cold days. If your thermostat exposes this setting, you can dial it back.
3. Reversing valve configuration (O vs. B). Most systems use O (energize in cooling). Trane and American Standard use B (energize in heating). A thermostat that can’t distinguish between O and B will short cycle or heat when it should cool. Every thermostat in this guide handles both.
How we picked
Four criteria, in this order:
- Does it expose AUX lockout numerically? A qualitative “eco” slider isn’t the same as setting 35°F.
- Does it expose the staging delta? This is the setting that stops strips firing on every setback recovery.
- O/B handled in software, so Trane and American Standard systems work without rewiring.
- Verified against the manufacturer’s own installer documentation, not a spec-sheet summary. Every number in this guide traces to a source listed in the page metadata.
We did not weight app design, screen resolution, or voice-assistant breadth. On a heat pump those are tiebreakers, not deciders.
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The 5 best thermostats for heat pumps
1. ecobee Smart Thermostat Premium
Best overall for heat pump efficiency.
The ecobee gives you the most granular heat pump controls of any consumer smart thermostat. In the installer settings you’ll find:
- Compressor Min Outdoor Temperature: default 35°F, adjustable 0–65°F or disabled. Below this, the compressor is locked out and AUX handles it alone.
- Aux Heat Max Outdoor Temperature: default 70°F, blocks AUX from running above this outdoor temp. Prevents AUX from staging up on mild days due to a big setpoint jump.
- Compressor to Aux Temperature Delta: how many degrees the room must lag before AUX stages up alongside the compressor.
- Aux Reverse Staging: when the room starts recovering, AUX drops out first (correct), then the compressor alone finishes the job.
Temperature data comes from ecobee’s internet weather service by address or from a wired outdoor sensor if you have one. The SmartSensor accessory handles indoor temperature averaging if you’re zoning by room.
Requires a C wire (or the included Power Extender Kit for no-C-wire installs). Supports up to 4H/2C heat pump systems.
→ Why Your Smart Thermostat Keeps Firing the AUX Strips has the full ecobee lockout walkthrough.
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2. Google Nest Learning Thermostat (4th gen)
Best without a C wire, and best if you want it to learn.
The Nest 4th gen added meaningful heat pump controls that earlier Nest models lacked. The key feature is Heat Pump Balance, which controls how aggressively the thermostat stages AUX:
- Max Comfort: runs heat pump and AUX together freely, prioritizing fast recovery
- Balanced: default, uses both but leans toward the heat pump
- Max Savings: delays AUX as long as possible, maximizes heat pump runtime
- Off + lockout temp: turns off the automatic Balance logic and lets you set a manual AUX lockout temperature
This is also the one pick here that runs without a C wire, using power-sharing off the Y or W circuits. If your wall has four wires and no common, this is the short list.
Outdoor temperature comes from Wi-Fi weather (no sensor input). The Nest does not expose the staging delta directly. Heat Pump Balance is a qualitative slider, not a degree setting. If you want numerical control over the balance point, the ecobee is better.
For the O/B reversing valve, the Nest sets this in the app during setup (it calls the choice “O” or “B orientation”). → Full wiring guide: Nest Thermostat Wiring For Heat Pump
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3. Honeywell Home T10 Pro
Best for pro installs and wired outdoor sensor accuracy.
The T10 Pro is an installer-oriented thermostat with solid heat pump controls accessible via installer setup codes:
- ISU 3120 (Balance point lockout): set the outdoor temperature below which AUX activates (similar to ecobee’s Compressor Min Outdoor Temp)
- ISU 3090 (Backup Heat Differential): 2-15°F gap before AUX stages up
- ISU 3110 (Upstage Timer): Off, 30 min, or up to 16 hours before AUX is allowed to fire
The T10 Pro’s biggest advantage: it accepts a wired outdoor temperature sensor (C7089U1006) via the S terminals. That gives it more accurate outdoor readings than Wi-Fi weather, which matters in climates where the local weather station is miles away.
The downside: the installer setup menu is not consumer-friendly. Most homeowners need a tech to configure ISU settings, or need to follow Honeywell‘s programming guide closely.
→ Honeywell Heat Pump Thermostat Wiring for the terminal layout.
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4. Emerson Sensi Touch 2
Best value if you already have a C wire, and the HomeKit pick.
The Sensi Touch 2 handles a 2H/2C heat pump with O/B configuration and standard AUX/emergency heat wiring, and it’s usually the cheapest way to get native Apple Home support on a heat pump.
Its AUX control is basic: you get emergency-heat handling and the O/B setting, but no numeric outdoor lockout or staging delta. If your winters are mild or you have gas backup rather than electric strips, that gap costs you little. If you heat with strips in a cold climate, spend up to the ecobee.
One correction worth knowing: the ST76 requires a C wire. The no-C-wire Sensi is the older ST55, which is a different (and less capable) thermostat.
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5. Honeywell Home T6 Pro
Budget heat pump pick.
The T6 Pro is the cheapest thermostat here that still does heat pump control properly: real O/B configuration and correct AUX/emergency-heat terminals, at roughly half the price of the T10 Pro.
Note the SKU. TH6220WF2006 is a 2H/1C heat pump thermostat (compressor plus one stage of backup). If your system has two stages of AUX, or two compressor stages, you want the TH6320WF2003 variant instead. Buying the wrong one is the most common mistake on this model.
Like the Sensi, its AUX controls are basic. It’s the right call when the budget is fixed and the alternative is a $25 builder-grade thermostat.
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What we considered and rejected
- ecobee3 lite. Good thermostat, but it tops out at 2H/2C and drops the deeper AUX threshold settings that justify picking ecobee for a heat pump in the first place.
- Nest Thermostat (2020). Cheaper than the Learning model, but its heat pump staging control is basic and it requires a C wire, which removes the main reason to choose Nest.
- Nest Thermostat E. Single-stage only. Not suitable for a heat pump with backup heat.
- Builder-grade non-programmables (~$25). They will run a heat pump. They will also fire your strips on every recovery, because they have no balance-point logic at all.
What about budget heat pump thermostats?
A $25 thermostat will wire to your heat pump and run it. It will also fire your AUX strips at every setback recovery and on any day below 40°F, because it has no balance-point controls. Over a heating season, the electric bill difference between a tuned ecobee and a dumb thermostat on a typical heat pump system is measurable. ENERGY STAR data suggests 8-23% savings from smart thermostat use in homes with central HVAC.
If AUX heat cost isn’t a concern (mild climate, gas backup, or very short heating season), a budget thermostat is fine. Otherwise, the ecobee or Nest pays for itself.
Which one should you get?
Get the ecobee if: you want maximum AUX control, you heat with strips (no gas backup), or you want numerical settings rather than a qualitative slider.
Get the Nest 4th gen if: you have no C wire, or you want a learning thermostat and don’t need fine-grained staging delta control.
Get the Honeywell T10 Pro if: a pro is installing it and will configure the ISU settings, or if outdoor sensor accuracy matters more than app polish.
Get the Sensi Touch 2 if: you want Apple Home and already have a C wire.
Get the T6 Pro if: the budget is fixed. Check the SKU against your staging.
All five support O/B wiring for both standard and Trane/American Standard systems.
Installing it, and when to stop
Swapping a thermostat is a 30-minute job on the 24V control side: kill power at the breaker, photograph the existing wiring, go by terminal letter and not wire color, and set O/B during setup.
Two things are worth handing to a pro. First, if you can’t identify which wire feeds AUX or emergency heat, don’t guess. Miswiring E can leave you with no backup heat on the coldest night of the year. Second, the ISU/installer menus on the T10 Pro genuinely need someone who’s configured them before, and a balance point set wrong costs more than the service call.
Thinking about getting a quote? Get matched with a local HVAC pro →. Useful if your system has aux/emergency-heat wiring you can’t identify, or you want the balance point set by someone who’ll stand behind it.
Frequently asked questions
Do I need a special thermostat for a heat pump? Not a “special” one, but one that correctly handles the O/B reversing valve and ideally one that exposes AUX heat lockout controls. All five above cover both requirements.
Can I use Nest with a heat pump? Yes. The Nest 4th gen supports heat pump wiring including O/B configuration and has Heat Pump Balance controls. Earlier models (Nest 3rd gen, Nest E) have limited heat pump control; verify before buying.
What does O/B mean on a thermostat? The reversing valve terminal. In cooling mode, most heat pumps energize the valve (O terminal). Trane and American Standard energize it in heating mode (B terminal). You set which mode applies during thermostat setup. Getting this wrong causes the unit to heat when it should cool.
Does my heat pump need a C wire? ecobee, Sensi Touch 2, and both Honeywell picks require one. The Nest 4th gen can run without a C wire using power-sharing. If your system has no common wire, the ecobee’s Power Extender Kit handles it.
Can a thermostat damage a heat pump? Incorrect O/B configuration or reversing valve wiring can cause the system to run in the wrong mode. A thermostat that doesn’t support AUX/emergency heat wiring properly can strand you without heat. Using a standard 24V thermostat with a mini-split (no Y/W/R terminals) can cause control board damage. See AUX Heat vs Emergency Heat for more on heat mode wiring.
How much can the right heat pump thermostat actually save me? ENERGY STAR puts smart thermostat savings at 8-23% for homes with central HVAC. On a heat pump specifically, most of that comes from keeping the electric strips off, which is exactly what the AUX lockout and staging delta settings control.
Where this fits
If you’re replacing an older unit, start with the wiring: thermostat wiring color codes and the heat pump wiring guide cover the terminal-by-terminal swap. If your strips are already running more than they should, AUX heat vs emergency heat explains which mode is firing and why. Still deciding between the two front-runners? Nest vs ecobee compares them head to head.
Sizing or replacing the heat pump itself, not just the thermostat? Our sister site covers cold-climate heat pump selection in depth.
Update log
- 2026-07-19. Initial publish. Five picks verified against manufacturer installer documentation. Corrected Sensi Touch 2 C-wire requirement and T6 Pro staging SKU. Next review: 2026-10-19.
Sources & verification
Last reviewed: 2026-07-19 · next review 2026-10-19
✓ Verified against a manufacturer or standards source
- ecobee SmartThermostat Premium: supports O/B wiring, Compressor Min Outdoor Temp (0-65°F or disabled), Aux Heat Max Outdoor Temp (default 70°F), Compressor to Aux Temp Delta, Aux Reverse Staging, Heat Differential; requires outdoor temp sensor or internet weather — https://support.ecobee.com/s/articles/Threshold-settings-for-ecobee-thermostats
- Nest Learning Thermostat 4th gen: supports O/B (set in app), Heat Pump Balance (4 modes), AUX lockout temp when Balance=Off; uses Wi-Fi weather for outdoor temp; supports up to 3 compressor stages + 2 AUX/alt stages — https://support.google.com/googlenest/answer/9248719
- Honeywell Home T10 Pro: supports O/B, balance point lockout ISU 3120, Backup Heat Differential ISU 3090 (2-15°F), Upstage Timer ISU 3110; accepts wired outdoor sensor C7089U1006 to S terminals — https://docs.honeywellhome.com/t10-t10plus-pro-product-data/Advanced%20Features.htm
- Standard heat pump wiring uses O/B terminal for reversing valve (O=cool in most, B=heat in Trane/American Standard; set in thermostat software) plus Y1, W2/AUX, E terminals — confirmed across Nest, ecobee, Honeywell installation guides
- ENERGY STAR certification: ecobee SmartThermostat Premium, Nest 4th gen, and Honeywell T10 Pro are ENERGY STAR certified — verified via ENERGY STAR product search
- Emerson Sensi Touch 2 (ST76) requires a C-wire; the older Sensi Wi-Fi (ST55) is the no-C-wire model — https://sensi.emerson.com/en-us/products/sensi-touch-2-smart-thermostat
- Honeywell T6 Pro SKU TH6220WF2006 supports 2H/1C heat pump; the 3H/2C variant is TH6320WF2003 — Resideo product data
⚠ Provisional — industry-average estimate, not a direct manufacturer/spec citation
- Retail prices fluctuate; no price is stated in this guide by design. Amazon listing data (price, rating, stock) must be re-verified via the Creators API before each review cycle.
- ecobee lineup naming (Premium / Enhanced) changes between model years; verify the current SKU at ecobee.com before purchasing
- Nest 4th gen is sold on Amazon only as a color-variant bundle including the temperature sensor; bare-unit availability varies
