Prepare Heating For Winter

Get your furnace ready for winter with filter replacement, basic inspection, and proper thermostat setup for safety and efficiency.

Why it matters#

A neglected heating system wastes energy, can fail during the coldest weather (when repairs take longest and cost most), and poses serious safety risks including carbon monoxide poisoning. Annual maintenance catches cracked heat exchangers—a dangerous condition that allows deadly CO into your home. An hour of fall prep keeps your family warm and safe.

What you'll need#

Tools#

• Screwdriver
• Vacuum with hose attachment
• Flashlight

Materials#

• New furnace filter (correct size and rating)
• Machine oil (for older furnaces)

Steps#

1. Replace your furnace filter#

Locate the filter slot (usually near the blower compartment) and slide out the old filter. Note the size and airflow direction arrow. Insert the new filter with the arrow pointing toward the blower. Plan to check monthly during heating season.

2. Clean around the furnace#

Vacuum dust and debris from around and on top of the furnace. Remove any items stored near the unit—furnaces need clearance and stored items are fire hazards.

3. Inspect visible components#

Look for rust, corrosion, or soot around the burner area. Check that the exhaust flue is connected and undamaged. If you have an older furnace with a standing pilot light, it should burn blue—yellow flames indicate a problem.

4. Test your heating system#

Turn on the furnace by raising the thermostat above room temperature. Wait for the system to start. A brief burning smell (dust burning off) is normal for the first run. Listen for unusual sounds—banging, squealing, or rumbling.

5. Program your thermostat for efficiency#

Set your thermostat to 68°F when home and awake; lower it 7-10 degrees when sleeping or away. This simple adjustment can save up to 10% annually on heating costs. Make sure batteries are fresh if your thermostat uses them.

6. Check carbon monoxide detectors#

Verify you have CO detectors on every floor, especially near bedrooms. Press the test button to confirm they work. Replace batteries if you haven't in the past year.

Pro tips#

• Schedule professional inspection in early fall—technicians check things you can't, like heat exchanger cracks and combustion efficiency
• Keep 2-3 spare filters on hand near the furnace so replacement is easy
• Reverse ceiling fans to clockwise (low speed) to push warm air down from the ceiling

Warnings#

• If you smell gas, don't flip any switches—leave immediately and call your gas company from outside
• If the burning smell persists beyond the first few minutes of operation, or smells like plastic/wire, shut off the system and call a professional

When to call a pro#

Call an HVAC technician ($60-150 for a tune-up) for annual professional inspection—they test combustion, check for carbon monoxide, and inspect the heat exchanger. Also call if you hear strange noises, smell gas or persistent burning, see rust or cracks, or if the system won't maintain temperature. Furnaces involve gas and electricity—professional inspection is well worth it.