How to Prepare Your HVAC System for a Michigan Winter

When winter settles across Macomb and Oakland Counties, heating systems work around the clock. Preparing your HVAC equipment in the fall prevents surprise emergency calls when the temperature plunges.

Test the Heating Cycle Early Do not wait for the first freezing night to turn your heat on. Switch your thermostat to HEAT mode on a mild autumn afternoon, set the temperature 3 degrees above room temperature, and observe the cycle. Listen for proper blower startup and verify warm air flows from registers within a few minutes.

Replace or Clean Furnace Filters A clogged filter restricts air across the heat exchanger, leading to overheating, higher electric consumption, and uneven room temperatures. Inspect your air filter every 30 to 60 days during heavy heating months.

Clear Surrounding Utility Space Keep a minimum of three feet of clear space around your furnace and water heater. Storing cardboard boxes, paint cans, or cleaning chemicals near heating equipment presents a fire hazard and restricts necessary combustion air.

Set Up Your Whole-Home Humidifier If your HVAC system features a whole-home bypass humidifier, switch the seasonal damper from "SUMMER" (closed) to "WINTER" (open). Replace the water panel evaporator pad if it is encrusted with minerals, and adjust the humidistat to approximately 35%–40%.

Inspect Outdoor Vents and Flues High-efficiency furnaces vent exhaust gases through PVC pipes extending through an exterior wall. Ensure these pipes remain clear of autumn leaves, overgrown bushes, and winter snow drifts. Blocked vents cause automatic system shutdowns through safety pressure switches.