Chicago HVAC Winter Preparation: Complete Homeowner Guide

Schedule a Professional Furnace Tune-Up

This is the most important step. A NATE-certified technician will inspect your heat exchanger for cracks, clean burners, test the igniter and flame sensor, check gas pressure, and verify all safety controls. Doing this in September–October means you beat the rush and get priority scheduling if issues are found.

Replace Your Air Filter

Start winter with a fresh filter. A new filter ensures maximum airflow and efficiency as your furnace works harder during cold months.

Test Your Thermostat

Switch to heating mode and raise the temperature setpoint to confirm the furnace fires up. Smart thermostat users should review and update their winter schedule.

Check All Carbon Monoxide Detectors

CO detectors should be replaced every 5–7 years. Test the batteries and press the test button on each unit. Place one on every floor and near all sleeping areas.

Inspect Your Vents and Registers

Walk through every room confirming supply and return registers are open and unobstructed. Blocked registers cause pressure imbalances that reduce comfort and efficiency.

Protect Your Outdoor AC Unit

While AC units are designed for outdoor exposure, removing large debris and loosely covering the top (not the sides) protects against falling ice and heavy snow. Never fully enclose the unit — moisture trapped inside causes rust and pest problems.

Check Your Humidifier

If you have a whole-home humidifier, inspect the water panel and replace it if needed. Set the humidistat to 35–40% for Chicago's winter conditions.