How to program a thermostat schedule
To program a thermostat schedule, set it 7 to 10°F lower in winter, or higher in summer, for about 8 hours a day, usually while you sleep or work. The Department of Energy says that can save as much as 10% a year on heating and cooling. Heat pumps need a thermostat built for them.
Programmable thermostat or smart model: which to use
You may not need to buy anything. Look at the thermostat already on your wall. If it has a schedule or program menu, you can start today.
If it only has up and down buttons, you have two upgrades to choose from. A programmable model runs the times you enter and stores several daily settings. You can override one without wiping the week's program. A smart model connects to Wi-Fi, can learn your habits, reports energy use and works from your phone. The Department of Energy says smart models are usually easier to use, and programmable ones cost less.
Check these before you buy:
- Compatibility with your heating and cooling system. ENERGY STAR lists this as the first thing to confirm.
- Heat pump functions, if you have a heat pump.
- The maker's own controller, if you have a very efficient system. ENERGY STAR suggests this for equipment such as an air conditioner rated 20 SEER or higher.
- Wi-Fi signal at the wall. A smart thermostat far from the router can drop off. A range extender can help.
The best thermostat schedule and where the thermostat sits
Think of this in two parts: where the numbers go in your day, and where the thermostat sits on the wall.
| Time of day | Winter | Summer |
|---|---|---|
| Home and awake | Your normal comfort setting | As high as is comfortable |
| Asleep or out, about 8 hours | 7 to 10°F below normal | 7 to 10°F above normal |
One long block does the work, so choose the 8 hours when the house is empty or everyone is in bed. A ceiling fan can help in summer. The Department of Energy says running one lets you raise the setting about 4°F with no loss of comfort, as long as someone is in the room.
The thermostat reads the air around it. Sun on the wall, a nearby lamp or a draft from a door can make it run at the wrong times. If yours is in a bad spot, moving it means moving low-voltage wiring, so have an HVAC tech or electrician do it.
How to program a thermostat schedule that fits your week
- Note your comfort numbers
Write down the temperature you like when you're home in winter and in summer. These become your baseline.
- Pick your 8-hour block
Use the longest stretch when everyone is asleep or out. Weekdays and weekends can differ if your thermostat allows it.
- Enter the setback
Program 7 to 10°F below your baseline in heating season, or above it in cooling season. Start at the smaller number if the house feels too cold or hot.
- Set the system type
Open the installer or equipment menu and confirm it says heat pump if that's what you have. Your thermostat manual shows where to find it.
- Watch for backup heat
On a heat pump, look for an aux or emergency heat indicator the first few cold mornings. If it comes on after each setback, reduce the setback.
- Review the first month
If your thermostat shows run time or energy use, compare a few weeks and adjust. Change the schedule again when the season flips.
What it costs to program a thermostat schedule
| Option | Cost | What to know |
|---|---|---|
| Program the thermostat you have | Free | Takes minutes and uses no parts |
| New programmable thermostat | Varies by model | Usually cheaper than smart models, per DOE |
| New smart thermostat | Varies by model and rebate | ENERGY STAR's Rebate Finder searches by ZIP code |
| Possible yearly saving | Up to about $90 | 10% of the $900-plus ENERGY STAR says an average household spends on heating and cooling |
Your saving depends on your climate, your energy prices and how far you set back.
Thermostat setback mistakes to avoid
- Setting back a heat pump by hand. If the drop makes the backup electric-resistance heat come on, you pay more, not less.
- Forgetting who stays home. The Department of Energy reminds owners to think about the comfort and safety of pets left in a warm house.
- Running exhaust fans for hours. Bath and kitchen fans pull out air you paid to heat or cool. DOE says to turn them off within 20 minutes unless they are made for continuous use.
- Buying before checking rebates. Some utilities pay incentives for certified smart models.
What homeowners say about using a programmable thermostat
If you're buying a smart thermostat, check utility and state rebates first. One owner paid about $20 for an ecobee after rebates. (Reddit)
Thermostat schedule questions
What is a good thermostat setback temperature?
The Department of Energy uses 7 to 10°F for 8 hours a day in its savings estimate. Lower the setting in fall and winter and raise it in spring and summer.
Should I set back a heat pump thermostat at night?
Only with a smart or programmable thermostat designed for heat pumps. A manual setback can trigger backup electric-resistance heat, which costs more to run.
How much does a smart thermostat save compared with a programmable one?
ENERGY STAR certifies smart models on field data, but its product page gives no single percentage. The saving comes from how far and how long you set back, so a well-used programmable model can do much of the same job.
What you’ll need
Sources: U.S. Department of Energy, ENERGY STAR
General guidance for U.S. homes, not professional advice. For gas, electrical and structural work, call a licensed pro.