Heating is the biggest thing your house spends energy on. Not the fridge, not the dryer, not the TV that is always on. According to the U.S. Energy Information Administration’s most recent household survey, space heating accounts for 42% of all the energy used in American homes. The average household spent $519 a year on it, and homes heated with fuel oil spent more than twice that.
Which means heating is also where small, boring fixes pay the most. You do not need a heat pump or a contractor to make a real dent this winter. You need a free afternoon, a few habits, and less than $100 in parts from the hardware store. Here is the plan, free stuff first, then the kit.
Start With the Free Stuff
1. Turn the thermostat back at night and when you are out
This is the biggest free lever you have. The Department of Energy says turning your thermostat back 7 to 10°F for 8 hours a day can save as much as 10% a year on heating and cooling. It recommends about 68°F while you are awake and lower while you sleep or are away.
The myth worth killing here: a cold house does not cost more to reheat than it saved. A house loses heat faster the warmer it is inside compared to outside, so every hour it sits cooler, it is losing less. A setback always wins. (The one honest exception is some heat pumps, which can kick on inefficient backup heat during a big recovery. If you have one, use smaller setbacks.)
2. Use your curtains like a solar panel
Free heat comes through the glass every sunny day. The Department of Energy’s advice is to open curtains on south-facing windows during the day to let the sun warm the house, then close them at night to keep the chill of cold glass out. It costs nothing and it is genuinely pleasant. Winter light is the best light.
3. Turn the water heater down to 120°F
Water heating is about 18% of home energy use, usually the second-biggest line after space heating. Many tanks ship set to 140°F, and DOE says dropping to 120°F cuts $36 to $61 a year in standby heat loss alone, plus more on the hot water you actually use. One nuance we covered in our fall cleaning guide: some health agencies prefer storing water hotter with a mixing valve. Read that section first if anyone in your house is immune-compromised.
4. Change the furnace filter
A clogged filter makes the whole system work harder for the same heat. ENERGY STAR says to check it monthly in heavy-use months and replace it at least every three months. Write the date on the edge so you are not guessing in February.
5. Flip the ceiling fan (and keep your expectations modest)
ENERGY STAR says to run ceiling fans clockwise on low in winter, which pushes warm air near the ceiling back down into the room. It is free and takes ten seconds. It helps most in rooms with tall ceilings. In a standard eight-foot room, the difference is small, and anyone promising a big percentage is guessing.
Find Where the Cold Gets In
Before you buy anything, spend fifteen minutes on a windy day finding the leaks. Run the back of your hand slowly around exterior doors, window sashes, electrical outlets on outside walls, and the attic hatch. Or light a stick of incense and watch where the smoke wavers. The usual suspects:
- The gap under exterior doors. If you can see daylight, you are heating the porch.
- Door and window edges where old weatherstripping has flattened or fallen off.
- Outlets and switches on exterior walls. There is often nothing behind the cover plate but a hole into a cold wall cavity.
- Old single-pane or leaky windows, especially ones you never open in winter.
Make a list, then go shopping once.
The Under-$100 Draft-Busting Kit
We priced a kit for a typical small house or apartment at Home Depot and Walmart on October 3, 2026. Prices move, but the total lands well under the line.
| Item | What it fixes | Price we found |
|---|---|---|
| Under-door draft stopper | Gaps under interior or exterior doors, no install | $12.77 |
| Self-stick door sweep | Daylight gap under an exterior door | $7.28 |
| Foam weatherstripping tape, 10 ft | Door frames and window sashes | $6.97 |
| EPDM rubber weatherstripping, 17 ft | Doors that get heavy daily use | $10.27 |
| Outlet and switch foam gaskets, two 6-packs | Drafts through exterior-wall outlets | $5.86 |
| Window insulation film kit (patio door size) | Leaky or single-pane windows you never open | $9.86 |
| Rope caulk, 45 ft | Gaps around window frames, removable in spring | $11.55 |
| 7-day programmable thermostat (Honeywell RTH221B) | Automatic setbacks, if you do not have one | $20.19 |
| Total | $84.75 |
How much does it save? We are going to be straight with you, because this is where a lot of articles get creative. ENERGY STAR says sealing air leaks and adding insulation can save up to 10% on annual energy bills. That figure includes insulation, which is not in this kit. A weekend with foam tape and a door sweep is a fraction of that job. What you will notice right away is comfort: no cold stripe across the floor, no curtain that moves when the wind blows. That alone lets most people set the thermostat a degree or two lower, which is where the money actually comes from.
How to Install It in One Afternoon
- Doors first. They are usually the worst offenders. Clean the frame with a damp cloth, let it dry, and apply weatherstripping to the stop where the door closes against it. Close the door on a dollar bill: if it slides out easily, you need a thicker strip. Then fit the sweep to the bottom of the door.
- Outlets and switches. Turn off the breaker, unscrew the cover plate, press the foam gasket in place, screw the plate back on. Two minutes each.
- Window gaps. Press rope caulk into the cracks around frames and sashes with your thumb. It peels off cleanly in spring.
- Window film last. Tape goes on the trim, the film goes on the tape, and a hair dryer shrinks it tight and nearly invisible. The Department of Energy notes that properly sealed plastic sheeting reduces air leaking through windows.
- Program the thermostat. Set a lower temperature for sleep and for the hours the house is empty, and let it do the remembering for you.
One thing to keep in mind once you have sealed up: a tighter house holds onto everything inside it, including moisture and fumes. Run the bathroom and kitchen fans, and crack a window for ten minutes when you are cooking or cleaning. We explain why in our fall cleaning checklist.
If You Have a Little More to Spend
These blow the $100 budget on their own, so treat them as either-or upgrades rather than add-ons.
- A smart thermostat (about $80). ENERGY STAR says certified models can save about $100 a year for homes with high bills or that sit empty during the day. If your bills are modest and you already use a programmable one well, the gain is smaller.
- Thermal curtains (about $40 a pair). Lined curtains on your coldest windows, closed at night, cut the chill radiating off the glass.
- Radiator reflector panels, if you heat with radiators on outside walls. The UK’s Energy Saving Trust says they are worth it behind radiators on uninsulated exterior walls and not worth it on interior walls.
If Money Is Tight This Winter
Two federal programs exist for exactly this, and plenty of people who qualify never apply.
- The Weatherization Assistance Program pays for professional air sealing, insulation and heating system work for households at or below 200% of the federal poverty level. DOE says it saves families an average of $372 or more a year. You apply through your state’s weatherization agency.
- LIHEAP, the Low Income Home Energy Assistance Program, helps pay heating bills directly. Eligibility and application are handled locally; HHS has the starting point.
Your utility may also run its own free home energy audits or rebate programs. It is worth a five-minute look at its website before you buy anything.
The Gear We Would Buy
Nothing fancy. These are the same items from the kit above, if you would rather have them show up at the door.
- Under-door draft stopper: the easiest win in the house, and it works on interior doors to keep heat in the rooms you use.
- Door sweep: for the exterior door with daylight under it.
- EPDM rubber weatherstripping: outlasts foam on doors you open a dozen times a day.
- Outlet and switch gaskets: the cheapest thing on this list, and the most overlooked.
- Window insulation film kit: buy the patio door size and cut it down for several windows.
- Rope caulk: seasonal, removable, renter friendly.
- Honeywell 7-day programmable thermostat: about twenty dollars to automate the biggest free saving you have.
If You Only Do Three Things
- Set back the thermostat 7 to 10°F at night and when you are out. Free, and the biggest lever.
- Seal the exterior doors with weatherstripping and a sweep. About $25.
- Turn the water heater to 120°F. Free, and you will forget you did it.
None of this is glamorous. All of it works the first cold night, and keeps working every night until spring. That is a pretty good deal for the price of a nice dinner!
Heating Bill FAQ
What temperature should I set my thermostat to in winter?
The Department of Energy suggests about 68°F while you are home and awake, and lower while you sleep or are away. Turning it back 7 to 10°F for 8 hours a day can save up to 10% a year.
Is it cheaper to leave the heat on all day?
No. A cooler house loses heat more slowly, so setting the temperature back saves energy even after you count the reheat. Some heat pump systems are the exception and do better with small setbacks.
Does window insulation film really work?
On leaky or single-pane windows, yes. It stops drafts and adds a still air layer against the glass. On modern double-pane windows that already seal well, the difference is small.
More ways to lower what your home costs to run: Energy & Bills · The sustainable home upgrades most people overlook · 7 eco-friendly upgrades that save you money · The fall cleaning checklist
Whole Earth Home is a participant in the Amazon Services LLC Associates Program. Links in this post marked as shopping links are affiliate links, and we may earn a small commission on qualifying purchases at no extra cost to you. Prices listed in the table were checked at Home Depot and Walmart on October 3, 2026.