When the temperature outside is too warm to justify cranking the heating system but too cold to leave the house at the thermostat's overnight setting, the right move is usually somewhere in between. Seven low-cost adjustments below cover the moves that homeowners can make on their own to keep the living space comfortable without driving the heating bill up. The list is organized roughly in order of impact, with the thermostat lever producing the largest annual savings and the secondary-heat-source decision producing the most direct shoulder-season comfort.
If you are an HVAC contractor looking for sharable customer content, feel free to send this guide to any homeowner asking about the in-between weather. The tips are written for the homeowner directly, but every section anchors back to the operational reality the contractor sees on service calls. Helping customers solve the easy stuff themselves earns trust and tends to surface the harder problems (failing system, undersized equipment, ductwork issues) that the contractor actually needs to address.
Install a Smart Thermostat
The thermostat is the single biggest lever a homeowner has on the heating bill. Upgrading from a manual dial to a programmable or smart thermostat pays back fast because the device handles the "turn it down overnight and up at 7 a.m." schedule that most homeowners forget to maintain by hand. A basic programmable thermostat costs $40 to $80 and typically saves $50 to $100 in the first year, which means it pays back inside the first heating season. A smart learning thermostat costs $150 to $250 and saves closer to $130 to $180 annually because it learns the household's actual patterns and shifts setpoints around real occupancy rather than around a fixed schedule. The payback window is longer (12 to 18 months) but the higher annual savings make it the better long-term choice for households with variable schedules.
The Department of Energy programmable-thermostat guide covers the basic schedule logic; most smart thermostats handle the schedule learning automatically once they observe a week or two of household routine. For HVAC contractors evaluating the smart-thermostat conversation as part of their service-call upsell, the software-stack features that integrate with smart thermostat data are worth a look.
Let in the Daytime Sun
The sun is the cheapest heat source on the planet, and most homes underuse it. The trick is sequencing the curtain and blind movements through the day so the rooms that face the sun catch the most heat at the right moments.
Morning: open east-facing window coverings before leaving for work. The 7 a.m. to 10 a.m. sun warms the rooms cheaply for the rest of the morning even after the sun moves off them.
Midday: open south-facing rooms fully. The 11 a.m. to 3 p.m. sun pours through south-facing windows and pre-heats the rooms that get the most evening use, like the kitchen and living room.
Late afternoon: open west-facing curtains for the 3 p.m. to sunset window. The low-angle late sun penetrates farther into the room than the high midday sun and adds another two to three hours of free heat before evening.
Close the Curtains After Dark
The same windows that bring in free heat during the day let the same heat back out after sunset. The trick is timing the curtain close to the moment outdoor temperature drops below indoor temperature, which usually happens within the hour after sunset. Some window coverings hold heat better than others:
- Cellular (honeycomb) shades: highest insulating value of any common window covering; the air pockets inside the cells trap heat against the glass.
- Insulated curtains: heavy fabric with a thermal lining; solid heat-retention boost for the cost.
- Lined drapes: moderate boost; the lining is the active layer.
- Standard curtains or blinds: modest boost; better than nothing but well below insulated options.
- Bare windows: zero retention; all heat at the glass escapes.
The Department of Energy window-coverings guide covers the technical R-values if a homeowner wants to compare specific products.
Reverse the Ceiling Fans
Most ceiling fans have a direction switch that flips the blade rotation between summer and winter modes. Hot air rises and pools at the ceiling; in winter, the fan running on low in reverse gently pushes that warm ceiling air back down into the living space.
Quick how-to: find the direction switch on the motor housing above the blade hub, flip it so the blades rotate clockwise when viewed from below, and run the fan on its lowest speed. Smart fans handle the same toggle through the app instead of a physical switch.
The point in winter is gentle circulation, not a breeze. High speed cools the occupants by accelerating evaporation off the skin, which is the opposite of what the room needs in the cold months. Run the fan continuously during occupied hours; the wattage on the lowest setting is a small fraction of what the heating system saves by avoiding the temperature drop near the floor.
Seal the Drafts
A house with leaky seals around windows, doors, and outlets loses heat faster than the heating system can replace it. The leaks are usually invisible to the eye but obvious to four simple detection methods:
- Hand test: run a hand slowly along window and door seams on a cold day. Cold spots are leaks.
- Smoke pencil or candle: hold the flame near suspected leak points and watch for the smoke to bend toward the gap. Use a candle or incense stick safely away from drapes and combustibles.
- Thermal camera (or phone app): modern smartphone apps can use the camera to detect temperature differences across surfaces. Cold streaks at window frames and outlet plates mark the leaks.
- Daylight inspection: at night, with interior lights on, walk around the outside of the house and look for light leaking out around door frames and window seals.
Once the leaks are found, the fixes are mostly DIY: adhesive-backed weather stripping for door and window frames, door sweeps for the bottom of exterior doors, foam outlet gaskets behind cover plates on exterior walls, and caulk for gaps in trim and around penetrations. The Department of Energy air-sealing guide covers the technical specifics if a homeowner wants to go deeper.
Move Furniture Off the Vents
The most common preventable comfort problem in the average home is a couch or bookcase parked over a floor register. The vent is delivering warm air into the back of the furniture instead of into the room. Before: the couch absorbs the warm air, the room stays cold, and the homeowner cranks the thermostat to compensate. After: the couch moves twelve inches off the vent, the warm air reaches the room, and the thermostat setting can come back down two or three degrees without losing comfort. Walk every room and check the registers: any vent blocked by furniture is a heating dollar going into the upholstery instead of the air.
Add a Secondary Heat Source
When the central heating system is sized for peak cold but the day calls for just a small comfort lift, a secondary heat source can fill the gap without running the whole house at heated temperature. Three options cover most homes.
Fireplace and Wood Stove
A wood-burning fireplace or stove is the highest-output secondary heat option, with a typical insert producing 20,000 to 60,000 BTU per hour. The tradeoff is fuel handling (cord wood storage, ash cleanup) and the safety upkeep (annual chimney sweep, clearance maintenance). For homes with an existing fireplace, the cost of using it for a few hours a night during shoulder weather is essentially the cost of the wood and a small efficiency loss through the chimney.
Electric Space Heater
An electric space heater is the right tool when the goal is to heat one room for a couple of hours rather than the whole house. The output range is typically 750 to 1,500 watts (about 2,500 to 5,000 BTU per hour). Modern ceramic heaters with built-in thermostats and tip-over shutoffs are safe to leave running unattended in the same room as the occupants. The operating cost runs about 12 to 25 cents per hour depending on the local electric rate, which is far less than running the central heating to warm a whole house for a single occupied room.
Heated Throws and Mattress Pads
The cheapest secondary heat is the heat applied directly to the occupant rather than to the room. A heated throw on the couch (35 to 50 watts) or a heated mattress pad on the bed (60 to 90 watts) keeps the user warm at a fraction of the energy cost of heating the surrounding air. The math is hard to beat: a heated throw running four hours an evening costs about 4 to 6 cents and replaces three to five degrees of room heating.
If the homeowner is running the seven moves above and the house still feels cold when the outdoor temperature is mild, the issue has moved out of homeowner DIY territory and into the HVAC system itself: an undersized unit, leaky ductwork, a failed sensor, aging insulation, or a heat pump operating outside its efficient range. The common-HVAC-mistakes framework covers what the contractor will check first, and the HVAC system selection guide covers what a replacement conversation looks like if the existing equipment is near end of life. For homeowners weighing the cost of a new system, the HVAC pricing math lays out what drives the install quote, and the HVAC technician training piece explains why finding a contractor with current continuing education matters more than picking the cheapest bid.
Smart Service for Field Service
If you are running an HVAC business and want a software stack that handles scheduling, dispatch, customer and equipment history, mobile invoicing, and the recurring service agreements that keep homeowners on a comfortable yearly maintenance cadence, Smart Service integrates with QuickBooks Desktop and QuickBooks Online and iFleet keeps techs in the field synced with the office. Try a free demo to see how it fits!
