Set your heat pump thermostat to 68°F and leave it there. Unlike furnaces, heat pumps lose efficiency with large setbacks. A 5°F setback that saves money with a furnace can actually cost more with a heat pump by triggering backup heat.
Home Electrification Experts — Full-Service Design to Install, 9 States
Ideal Temp
68°F
hold steady
Max Setback
2°F
heating season
Aux Lockout
10°F
recommended
Annual Savings
$500–$850
from lockout fix
Why Heat Pumps Need Different Thermostat Management
If you grew up with a furnace or boiler, you learned to manage your thermostat one way: crank it down at night, crank it up in the morning, and let the system blast hot air to recover. That strategy works with combustion heating because furnaces deliver 130-140°F air and recover from a setback in 15-30 minutes. Heat pumps are fundamentally different, and using furnace habits with a heat pump will cost you money.
A heat pump delivers air at 90-105°F — warm enough to heat your home comfortably, but not hot enough to rapidly recover from a deep temperature setback. When you drop from 68°F to 60°F at night and then ask the system to recover at 6 AM, the heat pump has to work for 1-3 hours to bring the house back up. During that recovery period, one of two things happens — and both are expensive.
Scenario A: Backup Heat Engages
If your thermostat detects that the heat pump can't recover fast enough, it engages electric resistance backup strips. These strips operate at a COP of 1.0 (compared to the heat pump's COP of 2.5-4.0), meaning they cost 2.5-4x more per BTU. At Massachusetts' $0.33/kWh rate, running 10 kW of electric strips for 2 hours costs $6.60 — roughly what the heat pump would spend heating your home all day.
Scenario B: Extended Low-COP Operation
If backup heat doesn't engage, the heat pump runs at maximum capacity for an extended period. At 6 AM on a 10°F morning, the outdoor unit is working at its hardest — and its COP is at its lowest (2.0-2.5). Extended full-capacity operation during the coldest hours uses far more electricity than steady-state operation throughout the night.
The Setback Penalty: Real Numbers
A Massachusetts homeowner with a 2,000 sqft home tested both approaches over two identical cold weeks in January 2025 (average outdoor temp 18°F):
- Week 1 — 8°F setback (68°F to 60°F at night): 520 kWh consumed = $172
- Week 2 — steady 68°F: 410 kWh consumed = $135
- Setback "savings" actually cost $37 MORE per week
The Best Winter Setting: 68°F, Hold Steady
Set your heat pump to 68°F and leave it there. Heat pumps work most efficiently at a constant temperature. Unlike furnaces, large setbacks (lowering temp 5-10°F at night) can actually cost more by triggering expensive backup heat during recovery.
This may feel counterintuitive if you've spent decades programming nighttime setbacks into your Honeywell thermostat. But the physics are clear: a heat pump maintaining 68°F throughout the night at a COP of 2.5-3.0 uses less total electricity than one that coasts down to 60°F and then sprints back up to 68°F using backup strips at a COP of 1.0.
Why Traditional Setbacks Don't Work
A furnace blasts 130°F air and recovers quickly from a setback. A heat pump delivers 90-105°F air — it recovers slowly. If you set back to 62°F at night, the morning recovery may trigger electric resistance backup heat at $0.33/kWh+ instead of the heat pump's efficient operation.
The Department of Energy traditionally recommends 7-10°F setbacks for furnace and boiler systems. That advice does not apply to heat pumps. The DOE and ENERGY STAR both acknowledge that heat pumps require different thermostat strategies, but this nuance is frequently missed by homeowners and even some HVAC installers.
Rule of Thumb
Limit setbacks to 2°F maximum. A 2°F setback (68→66°F at night) is fine. A 5°F+ setback (68→63°F) risks triggering backup heat and may increase your bill.
Recommended Schedule for New England Homes
The following schedule balances comfort, efficiency, and modest energy savings. It works for ducted and ductless heat pump systems throughout the New England heating season (October through April).
| Time | Setting | Why |
|---|---|---|
| Morning (6am–9am) | 68°F | Active period, comfortable waking temperature |
| Daytime (9am–5pm) | 66°F | 2°F setback if away — minimal, efficient |
| Evening (5pm–10pm) | 68°F | Comfortable evening temperature |
| Night (10pm–6am) | 66°F | 2°F setback for sleeping — saves 3-5% |
Summer schedule (May through September): Heat pumps in cooling mode behave more like traditional air conditioners. You can set back more aggressively in summer — 72°F when home, 78°F when away — without triggering efficiency penalties. The 2°F rule is a heating-season recommendation only.
Emergency and Auxiliary Heat Lockout: Your Biggest Money Saver
The single most important thermostat setting most homeowners never touch is the auxiliary heat lockout temperature. This setting determines the outdoor temperature below which the thermostat is allowed to engage electric resistance backup heat. Setting it correctly can save $300-$800 per winter.
Most thermostats ship with the aux heat lockout set to 35°F or 40°F — meaning whenever the outdoor temperature drops below 35°F and the heat pump can't keep up, electric strips kick in. In Massachusetts, outdoor temperatures are below 35°F for roughly 2,500 hours per heating season. That's a lot of expensive backup heat.
Modern cold-climate heat pumps (Mitsubishi Hyper-Heat, Daikin FIT, Bosch IDS) maintain rated capacity down to 5°F and continue producing useful heat to -13°F or lower. There's no reason to engage backup heat at 35°F with these systems. Set your aux lockout to 10°F or even 5°F with cold-climate equipment.
Factory Default = Money Drain
If your installer left the aux lockout at the factory default of 35\u201340°F and you have a cold-climate heat pump, you could be wasting $600\u2013$900 per year on unnecessary backup heat. Check this setting today.
| Lockout Setting | Hours of Aux Heat/Year | Extra Annual Cost |
|---|---|---|
| 40°F (factory default) | 800–1,200 hrs | $600–$900 |
| 25°F | 250–400 hrs | $200–$350 |
| 10°F (recommended for cold-climate HP) | 50–100 hrs | $40–$80 |
| 5°F (aggressive, CCHPs only) | 15–40 hrs | $12–$35 |
That's a potential savings of $500-$850 per year just from changing one setting. If your installer left the aux lockout at 35-40°F and you have a cold-climate heat pump, lower it to 10°F immediately. This is free money.
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Heat Pump Compatible Thermostats: Ecobee vs Nest vs Others
Not all smart thermostats work well with heat pumps. The right thermostat needs to understand multi-stage heat pump operation, backup heat staging, and the importance of avoiding aggressive setbacks. Here's our ranked recommendation list based on real installations across New England.
Ecobee Smart Premium
Best overall for ducted heat pumps
HP Compatible
Excellent
Aux Lockout
Yes
Room Sensors
Yes (included)
Honeywell T10 Pro
Dual fuel and complex systems
HP Compatible
Excellent
Aux Lockout
Yes
Room Sensors
Yes (optional)
Google Nest Learning
Homes with simple single-stage HPs
HP Compatible
Good
Aux Lockout
Limited
Room Sensors
Yes (optional)
Mitsubishi kumo cloud
Mitsubishi mini-split systems
HP Compatible
Excellent
Aux Lockout
N/A (no aux)
Room Sensors
No
Daikin One+
Daikin ducted systems
HP Compatible
Excellent
Aux Lockout
N/A (no aux)
Room Sensors
Yes
| Thermostat | HP Compatible | Aux Lockout | Room Sensors | Best For |
|---|---|---|---|---|
| Ecobee Smart Premium | Excellent | Yes | Yes (included) | Best overall for ducted heat pumps |
| Honeywell T10 Pro | Excellent | Yes | Yes (optional) | Dual fuel and complex systems |
| Google Nest Learning | Good | Limited | Yes (optional) | Homes with simple single-stage HPs |
| Mitsubishi kumo cloud | Excellent | N/A (no aux) | No | Mitsubishi mini-split systems |
| Daikin One+ | Excellent | N/A (no aux) | Yes | Daikin ducted systems |
Our top pick: Ecobee Smart Thermostat Premium. It has native heat pump mode that understands staging, a configurable aux heat lockout threshold, room sensors for multi-room averaging, and an occupancy sensor that enables gentle 1-2°F setbacks when you leave (not the 8-10°F swings that cause problems). At around $220, it pays for itself within a single heating season through smarter backup heat management.
A word on Nest: The Google Nest Learning thermostat is popular and works with heat pumps, but its "learning" algorithm was designed for furnace systems. It tends to program aggressive setbacks that trigger backup heat on cold mornings. If you use a Nest, disable the "Auto-Schedule" feature and program it manually using the schedule above. Also check the "Heat Pump Balance" setting — set it to "Max Savings" to prioritize heat pump operation over backup heat.
Avoid: Basic programmable thermostats without heat pump mode. They don't understand backup heat staging and may engage electric strips unnecessarily. We've seen homeowners spend $400-$600 more per winter because a $30 thermostat was running backup heat at 35°F instead of the heat pump.
Seasonal Thermostat Strategy for New England
New England's climate creates four distinct thermostat seasons, each with its own optimal approach:
Late Fall (Oct\u2013Nov)
Outdoor temperatures are 30\u201350°F. Your heat pump operates at COP 3.5\u20134.5 — this is its sweet spot. Set to 68°F and let it run. This is where you build your savings bank compared to oil or gas.
Setting
68°F steady
Deep Winter (Dec\u2013Feb)
Outdoor temperatures frequently drop below 20°F. Hold 68°F steady, allow only 2°F night setback, and make sure your aux lockout is set to 10°F or lower. This is the most expensive period — protect your efficiency here.
Setting
68°F hold, 2°F max setback
Early Spring (Mar\u2013Apr)
Temperatures swing wildly — 55°F one day, 25°F the next. Keep your heat pump in heating mode (don't switch to cooling yet). The system handles these swings efficiently because the average temperature is in the high-COP range.
Setting
Stay in heat mode, 68°F
Summer (May\u2013Sep)
Switch to cooling mode. You can use more aggressive setbacks in summer: 72°F when home, 78°F when away. The efficiency penalty for setbacks in cooling mode is much smaller than in heating mode because recovery doesn't involve backup electric strips.
Setting
72°F home, 78°F away
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Frequently Asked Questions
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How Much Electricity Does a Heat Pump Use? (By Home Size + Utility Rate)
A heat pump heating a 2,000 sqft New England home uses 8,000-12,000 kWh per year for heating. At Massachusetts rates ($0.33/kWh), that's $220-$330/month during winter — still 40-50% less than oil or propane.
Heat Pump Maintenance Calendar for New England Homes
Heat pumps need minimal maintenance: clean filters monthly, clear debris from the outdoor unit seasonally, and schedule professional service annually. This calendar covers every task by month for New England's climate.
Heat Pump Defrost Cycle vs Actual Problem: Troubleshooting Guide
A normal defrost cycle runs for 1-10 minutes every 30-90 minutes when frost builds up on the outdoor unit. If your unit defrosts constantly, runs for more than 15 minutes, or never defrosts, that's a real problem.