Complete the furnace maintenance checklist before temperatures drop

Key tips to remember

  • Retire your A/C system for the season with a proper cleaning, and protect it with a cover.
  • Change air filters, and check insulation and ductwork for inefficient gaps.
  • Remove floor vents and registers to vacuum out debris, and have chimneys and fireplaces cleaned.
  • Schedule a service appointment for your heating system for cleaning, care and inspection.
  • Look into a home protection plan for peace of mind during the busy holiday season.
Energy Saving Tips, Maintenance and Repairs

When pumpkin carving begins and NFL games return for Sunday-night viewing, the first drafts of heat usually start rising from the baseboards. As we transition away from running our air conditioning and into cooler months, now is a good time to conduct some furnace and A/C maintenance, which means putting your compressor to bed properly, checking the vitals of your heating system and cleaning the key components that keep everything running efficiently so you maintain indoor air quality. Winter is coming, so don’t delay in ticking down the items on this furnace maintenance checklist before you need to crank up the heat.

1. Clear around outdoor units.

Walk around your property, and clear all vegetation and debris away from your A/C compressor and exterior heat pump, keeping at least two to three feet of space clear around them. This ensures adequate airflow and helps prevent damage to the units.

2. Retire the A/C for the season.

Shut down your air conditioner for the winter by turning off the outdoor switch, which prevents it from turning on accidentally. If you live in an area prone to snowfall or windy storms, it’s a good idea to protect it with a cover. To clean the system, dump 1 cup of equal parts bleach and water into each of your air conditioner’s condensate drain lines. This kills algae and mold and helps prevent clogs.

3. Change air filters.

A rule of thumb is to check air filters every month and change them at least every three. A clean air filter will reduce indoor contaminants throughout the winter season and ensure proper airflow into your home. If you haven’t already, now is a good time to install updated high-efficiency, pleated air filters. These feature electrostatic charges that attract particles rather than allowing them to pass through, which filters dust, pollen, mold and dander more effectively.

4. Clean floor vents, registers and chimneys.

Remove floor registers, and vacuum out the ducts, which are magnets for dust, hair and food scraps — all of which pollute your home’s air and reduce efficiency, forcing you to crank up the heat. Move heavy furniture and other items that might block registers and strain your system, and make sure combustible products are safely stored away. If your home has a chimney and fireplace, it’s critical for fire safety to have them professionally cleaned and serviced every year.

5. Check insulation and ductwork.

When it comes to checking insulation, the general rule is that if you can see the tops of the joists in the attic, you’re not properly protected. Add a new layer of unfaced batt insulation perpendicular to the old layer, pushing the pieces together so they fit snugly side by side. If there’s more than an inch of joist showing, blown-in cellulose or fiberglass might fill the crevices better. Also check ductwork for open joints, dust buildup, mold and rust. Open joints can be resealed with duct tape, but corroded ducts need to be professionally repaired or replaced.

6. Schedule heating-system service.

Furnace maintenance begins with making a service appointment, in which a professional technician can provide essential cleaning, care and inspection. Annual servicing is typically less than $100 — that’s cheap when compared with the price of a new furnace or HVAC system. The following items are key steps for regular furnace maintenance, so ensure your technician addresses these areas. If performing DIY furnace maintenance, make sure to switch off electrical power and the fuel supply before touching any of the system’s components.

7. Start checks at the thermostat.

Turn up the thermostat, and listen for the furnace or heating system to turn on and run continually. If it shuts off within a few minutes, it could be a symptom of short cycling. That means the thermostat may need to be recalibrated or replaced or the heat exchanger in the furnace is overheating, and a safety device has shut it down. If you have a hot-water heating system, which has a boiler rather than a furnace, crank up the thermostat to let the temperature and pressure build up. Then, go down to the boiler room to check all visible pipes and valves for leaks and standing water. If you find a leak, call a professional. Check out our radiator maintenance for additional tips regarding hot-water pipes and vents.

8. Clean the combustion chamber and blower.

The combustion chamber is where fuel mixes with air and ignites to generate heat, which also results in carbon soot. A buildup of soot can cause the chamber walls to corrode, so clear it away by scraping with a small wire brush. Then, vacuum up any loose material, and inspect the chamber for holes or corrosion before replacing the cover. Also vacuum out the area that houses the blower, and check the blower belt for signs of wear and proper tension. A loose belt can slow the blower, compromising your system’s efficiency.

9. Change oil filters.

For oil-fired furnaces and boilers, replace the oil filter with an identical one every year. With the fuel supply turned off, you can unscrew the old filter and install the new one. Just be sure the old filter is disposed of properly. Oil nozzles tend to get clogged with buildup from impurities in the fuel. If your technician suggests replacing the nozzle, have them verify the new one has the correct flow rate and angle in case the model already in place is inaccurate.

10. Inspect the flue pipe.

Check for holes in the exhaust flue to prevent carbon monoxide leaks — particularly where the pipe meets the furnace. While small holes can be patched with foil tape, corroded flues must be replaced. Heating systems are vital for a comfortable holiday season. After you complete this important furnace maintenance checklist, look into how a home protection plan can help ease the stress from unexpected repairs and keep you and any potential house guests warm and cozy all winter long.


The information in this article is intended to provide guidance on the proper maintenance and care of systems and appliances in the home. Not all of the topics mentioned are covered by our home warranty or maintenance plans. Please review your home warranty contract carefully to understand your coverage.