Ecobee vs Nest for Heat Pumps (2025 Cold-Climate Test & Lockout Guide)
We ran both thermostats on a dual-fuel heat-pump system through a two-week cold snap to compare aux heat lockout, comfort, and real energy use. If you live where winters bite, the right lockout strategy can cut bills by 10–25%.
Related reading: Best Smart Thermostats in 2025 • DIY thermostat install • Best smart bulbs
Test setup & method
- Location: Upper Midwest (design temp ≈ −5°F / −21°C); two-week period with lows from 10°F to −8°F.
- System: 2-stage heat pump + gas furnace (dual-fuel), variable-speed blower, outdoor temp sensor available.
- Controls: Ecobee Smart Thermostat Premium with SmartSensor vs Nest Learning Thermostat (3rd-gen).
- Baseline: Balance point determined via prior utility seasons and degree-day analysis (≈ 25–30°F).
- Data: Runtime logs, aux heat calls, average setpoint error, and daily therms/kWh from the meter.
Heat pumps are most efficient above a certain outdoor temperature (your economic balance point). Below it, auxiliary heat (electric strips or gas furnace) may be cheaper or simply necessary to meet load. A smart thermostat that lets you lock out aux heat until you truly need it can save serious money without sacrificing comfort.
Feature comparison at a glance
| Feature | Ecobee Premium | Nest Learning (3rd-gen) |
|---|---|---|
| Aux heat lockout (manual set) | ✔ Explicit temp set (heat pump & aux) | ✔ With heat pump balance settings; less granular |
| Dual-fuel (heat pump + furnace) | ✔ Native, detailed staging options | ✔ Supported (Pro setup recommended) |
| Outdoor temperature source | ✔ Internet weather or wired sensor | ✔ Weather data; wired sensor via HVAC board |
| Room sensors | ✔ SmartSensor occupancy & temp | Optional Nest Temp Sensor (no occupancy) |
| Smart ecosystems | Alexa, Google, Apple Home, SmartThings | Google Home, limited Alexa |
| App control & data | Detailed runtime & staging logs | Good history; less granular on staging |
| Price* | $249–$299 | $199–$249 |
*Street prices vary; check rebates via the ENERGY STAR Rebate Finder.
Aux lockout & balance point
Outcome: Ecobee wins for granular aux lockout controls and clearer dual-fuel staging. We could set a firm aux lockout at 25°F and a compressor lockout at −5°F, matching our system’s performance curve.
- Ecobee: Separate lockouts for compressor & aux, plus minimum outdoor temp for heat pump operation. Easy to align with your calculated balance point. Great for power users.
- Nest: Heat pump balance (“Max Savings” to “Max Comfort”) and switchover settings work well but are less transparent. You may need a few days of observation to dial it in.
Comfort & recovery time
We targeted ±0.5°F setpoint error. With occupancy-aware set-backs at night, both thermostats recovered by 7 a.m., but:
- Ecobee leveraged its SmartSensor to avoid over-conditioning unoccupied rooms and kept average error lower during morning ramps.
- Nest recovered quickly too; Farsight and schedule learning remain the most intuitive experience.
Energy use & savings (our results)
In like-for-like outdoor conditions:
- Ecobee config: 14% fewer aux heat hours; 7–10% lower total heat energy versus permissive aux settings.
- Nest config: 9–11% fewer aux hours after tuning Heat Pump Balance; slightly higher aux calls on windy nights.
Tip: lockout temps only work if your home can actually hold the load. If set too low, you’ll get long run times and cold rooms. See DOE’s heat pump basics.
Dual-fuel specifics (heat pump + gas furnace)
With gas backup, your economic balance point depends on gas $/therm vs kWh and outdoor temps. Use last winter’s bills to estimate:
- Find average utility price per kWh and per therm.
- Get your heat pump COP curve from manufacturer literature.
- Compute the temp where heat pump cost ≈ furnace cost — that’s your economic lockout.
Ecobee lets you set switchover by temp with hysteresis so you don’t ping-pong between sources. Nest can too, but it’s less explicit; we recommend a Pro configuration if you have complex staging.
Which should you buy?
- Choose Ecobee Premium if you want precise lockouts, room-sensor comfort, Apple Home support, and detailed runtime data. Check price →
- Choose Nest 3rd-gen if you prefer simplicity, auto-schedule learning, and a premium metal dial. Plan on a few days of tuning for best aux behavior. Check price →
Either way, pair with your utility’s rebate or demand-response program to stack savings.
Step-by-step: set aux lockout temps
Ecobee Premium
- Menu → Settings → Installation Settings → Equipment → Heat Pump.
- Set Compressor Min Outdoor Temp (e.g., −5°F).
- Set Aux Heat Lockout (e.g., 25°F) and Heat Pump Lockout if needed.
- Menu → Sensors: enable SmartSensor averaging for occupied rooms.
Nest Learning (3rd-gen)
- Settings → Equipment → Continue → Heat Pump → Heat Pump Balance (start at “Balanced” or “Max Savings”).
- Settings → Temperature → Safety & Eco to fine-tune behavior.
- For dual-fuel, consider a Pro setup to expose manual switchover temps.
Need wiring help? See our DIY install guide and C-Wire explained.
FAQ
What’s a good starting aux lockout temperature?
In many homes, 25–35°F is a safe start. Tight, well-insulated homes can go lower; leaky homes may need higher. Verify comfort during the coldest nights and adjust 2–3°F.
Does a room sensor really help with heat pumps?
Yes. Sensors reduce over-heating unoccupied zones and help the thermostat anticipate recovery. Ecobee’s SmartSensor adds occupancy; Nest’s Temp Sensor provides temperature only.
Will this void any equipment warranties?
No — lockouts are standard control strategies. Always follow your OEM installer manual and, if unsure, consult a licensed HVAC pro.
