How to Winterize Your HVAC System for Winter

Written by Laurel | Nov 18, 2025, 5:00:00 AM

There are several things you can do to “winterize” your HVAC system before Winter really sets in. It is important to keep your system running in optimal condition when it needs to work it’s hardest.

Here is a handy HVAC Winterizing checklist:

  • Make sure to have your annual Heating Inspection Performed by certified professional
  • Ensure Electrical connections are properly plugged in
  • Replace air filters (every 3 months or every month if you have pets, high traffic)
  • Clean, vacuum vents, registers and returns
  • Check your thermostat, change batteries (if battery powered)
  • Check insulation, ductwork
  • Clear any accumulated clutter, leaves, debris from around the outdoor unit
  • Keep any snow, ice from accumulating on outdoor unit
  • Change direction of Ceiling fan rotation

Annual Heating Inspection

An annual heat inspection is very much like maintenance you have done for your car. It helps ensure the system is running at it’s best before the real hard work sets in. Air Doctor Heating and Air performs a 25+ point inspection to thoroughly check the system and all it’s components and provides you a written report.

A proper heating inspection offers peace of mind that helps keep your system running properly per the manufacturer’s specs.

It is also important if your system is under a manufacturer’s warranty. If a major component ever needs to be replaced, many manufacturers can require the maintenance records in order to honor the warranty.

Thermostats

While you winterize your HVAC system it is a great time to replace batteries in any thermostats that are powered by batteries. This will help be certain that your thermostat will be powered throughout the winter.

Thermostats vary greatly by make and model so it is best to consult your owner’s manual for exact instructions.

Air Filters

Air Filters should be replaced at least every three months and up to once a month if you have pets or high traffic. These air filters are important to keep contaminants minimized, but more importantly to allow proper air flow to the your hard working HVAC system. Extra strain on your HVAC system when it is running at maximum capacity can cause failures at the worst time.

Insulation, Ductwork

Insulation and ductwork should be checked before winter to make sure there is no displacement, holes, gaps or missing pieces. Replace may missing or damaged insulation to make sure heat in your home stays in your home and is not drafting out.

Splits in the ductwork can lead to costly heat escaping where you need it least. Tape and holes to prevent air from escaping. Have any damaged ductwork replaced as needed.

General Cleaning

Routine cleaning is always important, but special attention needs to be given a couple of times per year when it comes to your HVAC system. Always keep the general areas around your outdoor unit(s) free from clutter, debris, leaves, snow and ice. Keep the indoor unit accessible and free from clutter.

Thoroughly clean the vents, registers and returns, vacuuming and wiping them down to keep particulates from clinging to them.

Ceiling Fans

Changing the rotational direction of your ceiling fans from counter clockwise (Spring and Summer rotation) to clockwise (Fall and Winter). This simple step will help circulate the rising warm air back to your living space and is a great step to Winterize. Most ceiling fans have a switch located on the trunk to change the direction.

Conclusion

Winterizing your HVAC system will help make sure your system is ready to handle the upcoming, hard working season so that your home can be warm and comfortable until Spring. Contact Us at Air Doctor Heating and Air to schedule your annual maintenance inspection. Call or Text to 301-799-7200