The clocks fall back this Sunday, November 1. You get your hour back, it’s dark by dinnertime, and for most of the country this is the week the thermostat officially stops being decoration and starts being the most argued-over object in the house.
Which brings up the question we field every single fall, from homeowners and from more contractors than you’d expect: does turning the thermostat down at night actually save money, or does the system “work harder” in the morning and eat up everything you saved?
The short version: setbacks are real savings if you heat with a gas furnace, and a much more complicated story if you heat with a heat pump. Set a heat pump back the wrong way and you can genuinely spend more than if you’d left it alone. Here’s the whole picture, including the settings we’d actually program.
Table of Contents
- Why turning it down saves money (and the myth that won’t die)
- The numbers worth trusting
- If you heat with a gas furnace
- If you heat with a heat pump: read this before you touch anything
- Dual fuel systems and smart thermostats
- The settings we’d actually program
- A few honest cautions
- When no thermostat schedule will save you
Why Turning It Down Saves Money (and the Myth That Won’t Die)
The physics here is simple, and it settles the argument. How fast your house loses heat depends on the temperature difference between inside and outside. Keep the house at 70°F on a 30°F night and you’re fighting a 40-degree gap all night long. Let it drift down to 62°F and the gap shrinks, the house leaks heat more slowly, and your heating system burns less fuel to keep up.
The myth says the furnace then has to “work so hard” to recover in the morning that it cancels out the savings. It doesn’t. A furnace recovering from a setback runs longer, sure, but it’s replacing less heat than it would have spent maintaining 70°F for eight hours straight. The energy spent reheating the house is always less than the energy saved while it sat cooler. Every hour the house spends below your normal setting is an hour it’s losing less heat, and that’s money.
Where the myth earns a sliver of truth is with heat pumps, and we’ll get to that. But for a gas furnace, turning it down at night or while you’re at work is one of the only free energy upgrades that exists.
The Numbers Worth Trusting
We’re not going to invent a savings figure for you. The U.S. Department of Energy’s guidance is the one worth quoting: you can save as much as 10% a year on heating and cooling by turning your thermostat back 7 to 10 degrees from its normal setting for 8 hours a day. The DOE also notes the savings percentage runs higher in milder climates than in severe ones, which surprises people, but makes sense once you think about it. In a brutal climate the system still has to run hard even at the setback temperature, so the relative savings shrink.
What that 10% is worth in dollars depends on your fuel, your rates, and your house. If you’re heating with propane or oil this winter, the stakes are a lot higher per degree; we ran that cost math in our propane and oil heating guide earlier this month.
One more honest note: that DOE figure assumes you’re consistent. A setback you run seven nights a week beats one you remember twice a week, which is the whole argument for a thermostat that does it for you.
If You Heat With a Gas Furnace
Good news. Setbacks and gas furnaces get along great. Set it back at night, set it back while the house is empty during the day, and collect the savings. The furnace doesn’t care. It recovers from a setback the same way it does everything else: burner on, blower on, done.
A few furnace-specific pointers from the supply house side of the counter:
Single-stage furnaces recover fast
A single-stage furnace runs at 100% whenever it runs, so it pulls the house back up quickly. Recovery from an 8-degree setback is usually well under an hour in a reasonably tight home. Schedule the morning warm-up 30 to 60 minutes before the alarm and you’ll never feel the difference.
Two-stage and modulating furnaces may need a head start
Higher-end furnaces like to loaf along in low stage, which is great for comfort and efficiency but slower on recovery. Most will shift to high stage when the thermostat calls for a big temperature jump, but give them a bit more lead time in the schedule. If you’re shopping this category, our Goodman gas furnace guide walks through the staging tiers.
Don’t chase savings below about 60°F
You can set back too far. Deep overnight setbacks in a cold snap flirt with frozen pipes in exterior walls, and they let humidity and comfort problems creep in. Somewhere in the 60 to 64°F range overnight is the practical floor for most occupied homes.
If You Heat With a Heat Pump: Read This Before You Touch Anything
Here’s where we stop a lot of customers from hurting themselves.
A heat pump heats cheaply when the compressor is doing the work. It heats expensively when the electric backup strips kick in. Those strips are plain resistance heat, the same technology as a toaster, and they can cost two to three times as much to run per unit of heat as the compressor does.
Now picture what a big setback does. The house drifts down to 62°F overnight. At 6 a.m. the thermostat calls for 70°F. The compressor alone can only raise indoor temperature gradually, so a conventional thermostat sees that big gap, decides the heat pump is losing, and slams on the auxiliary strips to close it fast. You just paid toaster rates to claw back the heat you “saved” overnight. Run that routine every day and the setback can cost you money, not save it.
This is exactly why the DOE says programmable thermostats are generally not recommended for heat pumps in heating mode, and that a moderate, steady setting is usually the most cost-effective play. It’s also why “my aux heat runs every morning” is one of the most common calls we get in January. If that’s you, our auxiliary heat vs. emergency heat guide covers what those strips are doing and how to keep them in their lane.
So does a heat pump owner give up on setbacks entirely? Not quite. Three workable paths:
1. Keep it small
A 2 to 4 degree setback is usually shallow enough that the compressor can recover on its own without waking the strips. You give up some of the savings a furnace owner gets, but you keep all of it honest.
2. Use a thermostat with heat pump smarts
Modern smart thermostats with adaptive or intelligent recovery start the warm-up early and ramp back slowly on compressor power alone, locking out the aux heat unless it’s truly needed. The DOE specifically notes that thermostats with heat-pump algorithms make setbacks worthwhile again. If you go this route, make sure the thermostat is wired and configured for a heat pump, O/B terminal and all; our thermostat wiring guide keeps that from becoming an afternoon of guesswork.
3. Set it and leave it
Plenty of our heat pump customers just pick a number and live there all winter. Boring, and perfectly rational. With a variable-speed unit this is arguably the intended way to run it, since inverter systems are at their best holding a steady temperature at low speed.
And one thing we’ll say plainly: never use the EMERGENCY HEAT switch as a recovery shortcut. Emergency heat shuts the compressor out entirely and runs pure strip heat. It’s there for compressor failures, not Monday mornings.
Dual Fuel Systems and Smart Thermostats
A dual fuel setup, heat pump on top of a gas furnace, splits the difference nicely. The heat pump handles mild weather, the furnace takes over when it’s cold, and because the backup is gas rather than electric strips, morning recovery doesn’t carry the same penalty. Setbacks are back on the table. We covered who dual fuel makes sense for in our dual fuel guide.
As for smart thermostats generally: the hardware matters less than the schedule it runs. A fancy smart thermostat holding 70°F around the clock saves exactly nothing. What the good ones buy you is consistency, adaptive recovery, and aux heat lockout settings you can actually adjust. Those three features are the whole value.
The Settings We’d Actually Program
Gas furnace homes: 68°F or so while you’re home and awake, 60 to 64°F overnight and while the house is empty, with the warm-up scheduled 30 to 60 minutes before you need it. That lands you right in the DOE’s 7-to-10-degree, 8-hour sweet spot twice a day.
Heat pump homes with a basic thermostat: pick a steady temperature you can live with, or run a modest 2 to 4 degree overnight setback. Watch for the AUX indicator during morning recovery. If it lights up daily, shrink the setback.
Heat pump homes with a smart thermostat: enable adaptive/early recovery, confirm the aux lockout settings, and then a deeper setback is reasonable. Give it a week and check whether aux runtime moved; most smart thermostats will show you.
Everyone: this weekend, while you’re resetting the microwave clock, is the natural moment to load the winter schedule, swap the filter, and make sure the program reflects when people are actually home now, not your schedule from two years ago.
A Few Honest Cautions
If you run a whole-home humidifier, know that deep setbacks raise the relative humidity as the indoor air cools, and that can show up as fogged or dripping windows on cold mornings. Mild setbacks mostly sidestep this; otherwise, dial the humidifier down a notch when outdoor temperatures drop.
Radiant and in-floor systems respond too slowly for daily setbacks to make sense. High-mass systems like those want a steady target.
And if you’re leaving for weeks rather than hours, that’s a different playbook entirely, which we covered in our empty-house winter guide.
When No Thermostat Schedule Will Save You
A setback schedule is a tune, not a transplant. If the system takes three hours to recover from a modest setback, short cycles constantly, or leans on aux heat even in mild weather, the problem is the equipment or the sizing, not the thermostat. Our free HVAC sizing tool is a good first sanity check, and if the math says it’s replacement time, buying direct is where the real money gets saved. We stock Goodman furnaces and heat pumps at wholesale-direct pricing, with free shipping on orders over $99 and 0% APR financing through Affirm.
Questions about whether your setup can handle a setback schedule, or which thermostat plays nice with your heat pump? Call us at (877) 843-4822 or drop us a line. We answer this stuff all day, and we’d rather you get the free savings than find out in March that your heat strips ran all winter.