The seasons are changing, and your furnace is working overtime. As the weather cools, you may hear the age-old debate: is it cheaper to set your thermostat back when you leave or at night, or does the furnace just work harder to catch up? What you really want to know is “does turning your thermostat down really save you money?”
Let’s settle this common misconception once and for all.
🥶 THE MYTH: “Setbacks Don’t Save Money—The Furnace Just Works Harder.”
The idea here is that if you let your home temperature drop from, say, 70°F to 60°F while you’re at work, your furnace will have to run continuously for an hour upon your return, essentially negating any savings.
This is FALSE.
The notion sounds logical, but it ignores the basic physics of how heat works.
✅ THE FACT: Setting Your Thermostat Back Absolutely Saves You Money.
This is the consensus from the U.S. Department of Energy, energy experts, and HVAC professionals across the country. Here’s why the energy-saving setback strategy works:
1. The Rule of Heat Loss (Physics Wins)
Heat naturally flows from warmer spaces to colder spaces. The rate of heat loss depends directly on the difference between the temperature inside your home and the temperature outside.
When your home is 70°F (and it’s 30°F outside): The 40-degree difference causes heat to escape quickly. Your furnace has to run more often to replace the heat that is constantly escaping.
When your home is 60°F (and it’s 30°F outside): The 30-degree difference slows down the rate of heat loss.
By allowing the temperature to drop, you reduce the rate at which you lose heat, saving energy for the entire period the temperature is set lower. The energy used during the recovery period is far less than the energy saved while your home was losing heat at a slower pace.
The Experts Say: The U.S. Department of Energy estimates you can save as much as 10% a year on heating costs by setting your thermostat back 7°-10°F for 8 hours a day.
2. The Smart Solution: Why a Setback is Easy with a Smart Thermostat
The biggest challenge with manual setbacks is remembering to do them and timing them perfectly so your home is comfortable when you arrive. That’s where a smart or programmable thermostat becomes a game-changer.
| Feature | How It Maximizes Savings |
| Scheduled Setbacks | Automatically lowers the temperature 30 minutes after you leave for work and starts bringing it back up 30 minutes before you return. |
| Geofencing | Uses your phone’s location to know when the last person leaves and the first person returns, optimizing the schedule without you doing anything. |
| Optimized Recovery | A smart thermostat “learns” how long it takes your specific furnace to raise the temperature 10 degrees, ensuring it only runs long enough to hit your target by the time you walk in the door. |
🛠️ Key Takeaway for Northern California Homeowners
If you want to maximize your savings this winter, the strategy is simple: lower the temperature when you are asleep or away from home for eight hours or more.
When You’re Awake: Set it to a comfortable temperature (around 68°F).
When You’re Asleep or Away: Set it back 7°F to 10°F.
If you are still adjusting a traditional thermostat twice a day, it’s time to upgrade! The energy savings from a professionally installed smart thermostat will often pay for the unit within the first year.
Ready to start enjoying comfort, control, and guaranteed savings?
Contact Climate & Energy Solutions to explore high-efficiency smart thermostats, furnace maintenance plans, and solar solutions.