Quick answer
For most homes, set a heat pump to Heat mode, fan on Auto, and a steady temperature around 68°F, and keep nighttime setbacks small (about 1–3°F). Heat pumps work best holding a steady temperature. Big setbacks force a long morning recovery that often switches on expensive electric backup heat, wiping out the savings. If your thermostat lets you, also set an auxiliary heat lockout so backup heat only runs when it’s genuinely cold outside.
Recommended winter settings at a glance
| Setting | Recommended | Why |
|---|---|---|
| Mode | Heat | Not Auto (can flip to cooling) and not Emergency Heat (expensive backup only) |
| Fan | Auto | “On” blows room-temperature air between cycles, feels drafty and wastes energy |
| Temperature while home | ~68°F (adjust for comfort) | The Department of Energy’s general winter recommendation |
| Night or away setback | 1–3°F, or more only with a heat-pump-aware smart thermostat | Avoids triggering backup heat during recovery |
| Vacation (several days) | ~55–60°F | Long absences make a deeper setback worthwhile |
| Aux heat lockout (all-electric) | Around 25–40°F outdoor, lower for cold-climate units | Keeps electric strips off in mild weather |
| Dual-fuel switchover | Based on your fuel prices, often 25–40°F | Uses whichever heat source is cheaper |
| Equipment type in thermostat setup | Heat pump, with correct O/B reversing valve setting | Wrong setup causes cold air and errors |
These are starting points. Your installer may recommend different values for your specific equipment and climate.
Should you turn your heat pump down at night?
You’ve probably heard the standard advice: the Department of Energy says turning your thermostat back 7–10°F for 8 hours a day can save up to 10% a year on heating and cooling (DOE). That works well for gas furnaces, which can reheat a house quickly. Heat pumps are different. DOE itself notes that ordinary programmable thermostats generally aren’t recommended for heat pumps in heating mode, because of how they recover (DOE).
Why big setbacks can backfire
- At night, the house cools to, say, 60°F.
- In the morning, the thermostat calls for 68°F, an 8-degree jump.
- A heat pump delivers gentle, steady heat, so recovery is slow. Many thermostats see the big gap and turn on auxiliary electric heat strips to speed things up.
- Those strips use roughly two to three times as much electricity per unit of heat as the heat pump. A few hours of strip heat can erase the night’s savings.
What to do instead
| Your thermostat | Recommended approach |
|---|---|
| Basic programmable (not heat-pump-aware) | Keep setbacks to 1–3°F, or none |
| Smart thermostat with heat pump “smart recovery” or adaptive recovery | Moderate setbacks (around 3–5°F) are usually fine, since it starts warming early using the heat pump alone |
| Thermostat with an aux heat lockout set (backup can’t run above a set outdoor temperature) | Moderate setbacks can work in mild weather; keep them small on very cold nights |
| Dual-fuel system (gas furnace backup) | Larger setbacks are more forgiving, since the furnace recovers quickly |
| Ductless mini splits (no strip heat) | Small setbacks are fine; very large ones mean slow recovery |
For most heat pump owners, the simplest, cheapest strategy is to pick a comfortable temperature and leave it there.
Auxiliary heat settings: the biggest money-saver most people miss
Auxiliary (aux) heat is your backup, usually electric heat strips in the air handler. It turns on automatically when the heat pump can’t keep up or when the thermostat wants to warm the house quickly. Used sparingly it’s fine; used too much it can double your winter bill.
Set an aux heat lockout
Many smart and professional thermostats let you set an outdoor temperature above which aux heat can’t run. This keeps strips off in mild weather when the heat pump can easily handle the load.
| Heat pump type | Typical aux heat lockout (outdoor temperature) |
|---|---|
| Standard single- or two-stage heat pump | Around 35–40°F |
| Variable-speed heat pump | Around 25–35°F |
| Cold-climate heat pump, properly sized | Around 5–20°F, or as your installer advises |
Also check the aux heat threshold (how far below the setpoint the room must fall before aux heat turns on). A larger value, such as 2–3°F, means aux heat runs less often. Lockout temperatures depend on your heat pump’s capacity and your home, so confirm with your installer before setting them aggressively; if the heat pump can’t keep up, the house will get cold.
Dual-fuel: when to switch to the furnace
With a gas furnace as backup, the thermostat switches from heat pump to furnace below a set outdoor temperature (the switchover or “balance point” setting). The cheapest switchover depends on your gas and electricity prices.
Divide your electric rate (per kWh) by your gas price (per therm), then use this table for a typical cold-climate heat pump with a 95% furnace:
| Your price ratio | Heat pump is cheaper than gas down to about |
|---|---|
| 0.13 or higher | ~45–50°F (gas is cheaper most of the winter) |
| ~0.11 | ~30–35°F |
| ~0.09 | ~15–20°F |
| ~0.07 | ~0–5°F (run the heat pump nearly all winter) |
Example: electricity at 18¢/kWh and gas at $1.50/therm gives a ratio of 0.12, so a switchover around 35–40°F is reasonable. Standard (non-cold-climate) heat pumps lose efficiency faster in the cold, so their switchover is usually a bit higher.
With propane or oil backup, the heat pump is usually cheaper at almost any temperature it can run, so set the switchover as low as your heat pump can comfortably handle.
Smart thermostat settings to check
Menu names change with software updates, so treat these as what to look for rather than exact paths. If you’re not comfortable in installer menus, ask your HVAC contractor to set them.
| Thermostat | Settings worth checking | What to set |
|---|---|---|
| Ecobee | Installation settings → Thresholds: Aux Heat Max Outdoor Temperature, Compressor Min Outdoor Temperature (dual-fuel), Heat Differential, Smart Recovery | Aux lockout per the table above; compressor minimum = your dual-fuel switchover; Smart Recovery on |
| Google Nest | Equipment settings: Heat Pump Balance (Max Comfort / Balanced / Max Savings) and auxiliary heat lockout options | “Max Savings” or “Balanced” limits aux heat; set a lockout temperature if offered |
| Honeywell / Resideo (T-series, many professional models) | Installer setup: equipment type, auxiliary heat lockout, compressor lockout (dual-fuel), adaptive intelligent recovery | Lockouts per the tables above; adaptive recovery on |
| Any thermostat | Equipment type and reversing valve (O/B) setting | Must match your heat pump, or heating and cooling can be reversed |
Settings for ductless mini splits
Mini splits are controlled by their own remote or app, and they behave a little differently:
- Use Heat mode, not Auto, in winter.
- Set a temperature and leave it. Mini splits are most efficient running steadily at low speed. Turning them off when you leave and back on later makes them work harder to recover.
- Expect to set it a little higher. The unit’s sensor is often in the indoor head, high on the wall where air is warmest, so you may need a setpoint 1–3°F higher than you’d use on a wall thermostat. A remote or wall-mounted sensor (offered by many brands) fixes this.
- Point the vanes down. Warm air rises; aim it toward the floor in heating mode.
- Fan on Auto. It lets the unit modulate quietly.
- Use the freeze-protection mode when away. Many brands offer a low-temperature setting (often labeled 10°C, 46°F or 50°F heat) that keeps an unused space from freezing without heating it fully.
- Clean the filters every 2–4 weeks in heavy use; clogged mini split filters cut heat output quickly.
Common heat pump thermostat mistakes
- Using Emergency Heat as a “boost.” EM heat shuts off the heat pump and runs only backup heat, the most expensive way to heat. Use it only when the heat pump is broken or iced over.
- Big nighttime setbacks on a basic thermostat. Recovery triggers aux heat and can cost more than it saves.
- Cranking the setpoint up to warm faster. A heat pump doesn’t heat faster at 78°F than at 70°F; it just runs aux heat longer. Raise it a degree or two at a time.
- Fan set to On. It circulates room-temperature air between cycles, feels drafty, and adds electricity use.
- Auto mode in winter. On a sunny afternoon, Auto can switch to cooling, then back to heating.
- Wrong equipment setup after a new thermostat. If it’s set as a furnace or the O/B setting is wrong, the heat pump may blow cold air in Heat mode.
- No aux heat lockout. Without one, backup strips may run even on 45°F days.
- Turning mini splits off and on. Steady operation is more efficient and comfortable.
- Judging by vent temperature. Heat pump air feels warm, not hot (about 85–100°F). That’s normal; watch whether the room holds temperature instead.
Frequently asked questions
What temperature should I set my heat pump to in winter?
Around 68°F while you’re home is a good, efficient starting point, the Department of Energy’s general recommendation. Adjust a degree or two for comfort, then leave it steady.
Should I turn my heat pump down at night?
Only a little (1–3°F) unless you have a heat-pump-aware smart thermostat with smart recovery. Large setbacks often trigger expensive auxiliary heat in the morning.
Is it cheaper to leave a heat pump on all the time?
Generally, yes, at a steady temperature. Heat pumps are most efficient running long, steady cycles, and avoiding big recoveries keeps backup heat off.
Why does my thermostat say “Aux heat”?
The backup heat is running, usually electric strips, because the heat pump needs help, the system is defrosting, or you raised the setpoint a lot. Occasional aux heat on cold mornings is normal; constant aux heat in mild weather means the settings or the equipment need attention.
What’s the best fan setting for a heat pump in winter?
Auto. “On” circulates air between heating cycles, which feels cool and uses more electricity.
What temperature should I set while on vacation?
Around 55–60°F protects pipes and saves energy. Avoid turning the system off in freezing weather.
Related guides
- Heat Pump Running Constantly in Winter: Normal or a Problem?
- Emergency Heat on a Heat Pump: When to Use It and What It Costs
- Heat Pump Defrost Cycle: What Is Normal and What Is Not
- Heat Pump Backup Heat: Electric Strips vs Furnace Backup
- Heat Pump vs Gas Furnace: Total Cost Over 15 Years
- Heat Pump Blowing Cold Air in Heat Mode: 9 Causes and Fixes
This guide is general information. Settings depend on your equipment, home and climate; your installer’s recommendations for your specific system take priority. Installer menus can affect how your system operates, so change them carefully.