EcoGuide · Smart Thermostats · Updated 2026-10-12 · 900 words
Smart Thermostat Settings That Actually Lower Your Energy Bill
The Short Answer
A smart thermostat saves money only through the temperatures it holds while you are asleep or away. ENERGY STAR puts the average saving from certified smart thermostats at approximately 8% of heating and cooling bills or $50 per year. The Department of Energy says you can save as much as 10% per year on heating and cooling by turning the thermostat down 7–10°F for 8 hours a day.
So the settings that matter are the setback (how far it drops) and how long it holds it. Everything else is convenience.
The Settings That Matter
ENERGY STAR’s programmable thermostat guidance gives an illustrative schedule. Summarized:
| Period | Heating | Cooling |
|---|---|---|
| Wake and evening (home) | 70°F | 78°F |
| Day (away) | Set back at least 8°F | Set up at least 7°F |
| Sleep | Set back at least 8°F | Set up at least 4°F |
- Use a real schedule, not just “eco” when you remember. Eight hours a night plus a workday away is where the DOE’s 10% comes from.
- Turn on occupancy or away detection if your thermostat has it, so the setback starts when the house empties rather than at a fixed time.
- Leave early start (smart recovery) on. It brings the house back to temperature by the time you wake or get home, which makes a deeper setback easier to live with.
- Don’t fight the schedule. Every manual override to a higher temperature eats into the saving. If you keep overriding, adjust the schedule instead.
Heat Pumps Need Different Rules
If you heat with a heat pump, a deep setback can backfire. When the thermostat asks for a big jump in the morning, many systems bring on electric resistance backup heat, which costs far more to run. The Department of Energy’s advice: do not set back the heat pump’s thermostat manually if it causes backup electric-resistance heating to come on.
- Use a smaller setback (2–4°F) and a longer recovery window.
- Make sure the thermostat is configured as a heat pump, with auxiliary heat lockout set if it offers one.
- Watch for “aux” or “emergency” heat on the display after setbacks. See our aux vs emergency heat guide.
Features Worth Knowing About
- Utility demand response. ENERGY STAR notes that certified smart thermostats must be able to work with utility demand response programs. Many utilities pay a sign-up bonus or bill credit for letting them nudge your setpoint a few degrees on peak days.
- Rebates. Use the ENERGY STAR rebate finder with your ZIP code before buying. ENERGY STAR says most programs do not require you to join demand response.
- Remote sensors help when the thermostat sits in a hallway that is warmer or cooler than the rooms you use.
- Energy reports show runtime by day. Rising runtime in mild weather can mean a dirty filter or a system problem.
When a Smart Thermostat Won’t Save Much
- You already keep a steady, modest temperature and someone is home all day.
- Your heat is a boiler with radiators that responds slowly; setbacks still help, but less.
- Most of your bill is not heating and cooling. See our smart thermostat savings guide for the numbers.
Thermostats We’d Buy
We may earn a commission if you buy through these links, at no extra cost to you. Products are chosen on published specifications; we do not test them in-house (how we choose).
ecobee Smart Thermostat Essential
A lower-cost ENERGY STAR smart thermostat with schedules and away detection.
Check price on Amazon
ecobee Smart Thermostat Premium
Adds a remote room sensor in the box, useful when the thermostat location is not representative.
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Frequently Asked Questions
What is the best temperature setting to save money?
ENERGY STAR's example schedule uses 70°F for heating and 78°F for cooling when you are home, with a setback of at least 8°F in winter when you are away or asleep, and a setup of at least 7°F (4°F overnight) in summer.
How much can a thermostat setback save?
The Department of Energy says turning your thermostat down 7 to 10°F for 8 hours a day can save as much as 10% a year on heating and cooling.
Should I use setbacks with a heat pump?
Carefully. The DOE advises against manual setbacks that cause backup electric-resistance heat to come on. Use small setbacks and a thermostat configured for a heat pump.
How much does a smart thermostat save?
ENERGY STAR puts the average at approximately 8% of heating and cooling bills, or $50 a year.
Does turning the heat back up use more energy than leaving it on?
For furnaces and boilers, no: a house loses less heat when it is cooler, so the setback saves more than the recovery costs. Heat pumps are the exception if recovery triggers backup resistance heat.
Related Guides
- How much smart thermostats save — the evidence
- Emergency heat vs auxiliary heat — for heat pump owners
- Nest Eco mode explained — Nest's version of setbacks
- 2026 electric rate hikes — why the savings are worth more now
