Heating TipsJoliet, IL

How to Prepare Your HVAC
for Illinois Winter

Published April 2026 • Heavy Duty Heating & Cooling

Illinois winters are not gentle. Joliet regularly sees temperatures below zero. The best time to prepare is September or October — before the first cold snap hits.

Best time to schedule: September or October. Once November arrives, HVAC companies get very busy with emergency calls. Book your fall furnace tune-up early.

Step 1: Schedule a Professional Furnace Tune-Up

A professional tune-up includes: cleaning burners and heat exchanger, testing the flame sensor, inspecting the ignitor, checking gas pressure, inspecting the flue and venting, checking the heat exchanger for cracks (critical CO safety check), testing all safety switches, and a full heating test. Call (815) 212-7662.

Step 2: Replace Your Air Filter

A clogged filter is the most common and most preventable cause of furnace problems. Replace before the heating season. In Illinois, change every 60-90 days during active heating. Use MERV 8-11 for most homes.

Step 3: Test Your Thermostat

Set to HEAT and above current room temp. Confirm warm air from vents within 5 minutes. Set your winter schedule now on smart thermostats — a common mistake is leaving summer cooling schedules active into fall.

Step 4: Check Your Vents and Registers

All supply and return vents must be open and unobstructed. Closing vents in unused rooms does NOT save energy — it creates pressure imbalances that stress and damage the system over time.

Step 5: Inspect Your Furnace Area

Clear all flammable materials within 3 feet. Confirm access door is fully closed and latched. Check that the condensate drain line on high-efficiency furnaces is clear. Confirm flue pipe connections are secure with no rust or disconnection.

Step 6: Check Carbon Monoxide Detectors

CO is odorless and colorless. Before every heating season: test every detector, replace batteries, and replace any detector over 5-7 years old. Install detectors on every level including near sleeping areas. If a CO detector alarms — evacuate immediately and call 911.

Step 7: Know What to Do During Extreme Cold

Know where your furnace shutoff is located. Save our number now: (815) 212-7662. Keep your thermostat at 65 degrees or above when away from home to prevent pipe freezing.

Schedule Your Fall Furnace Tune-Up in Joliet

Heavy Duty Heating & Cooling provides professional furnace maintenance for Joliet and surrounding areas. Book before the rush. Bilingual EN/ES.

Call (815) 212-7662Maintenance Page

Frequently Asked Questions

When should I schedule my furnace tune-up in Joliet IL?

September or early October, before heating season. HVAC companies get very busy in November with emergency calls. Early scheduling gets priority service and time to repair anything found. Call (815) 212-7662.

How often should I change my furnace filter in Illinois?

Every 60-90 days during active heating season. Every 30-45 days if you have pets, allergies, or a dusty home. Check it monthly during heavy use.

What temperature should I keep my home in Illinois winter?

Keep thermostat at 65 degrees or higher even when away to prevent pipe freezing. During polar vortex events, 68-70 degrees is safer.

What are signs my furnace heat exchanger is cracked?

Unusual smells from vents, CO detector alarming when furnace runs, or family members with headaches that go away when leaving home. This is a carbon monoxide emergency. Call (815) 212-7662 immediately.

About Heavy Duty Heating & Cooling: Family-owned HVAC in Joliet, IL. Licensed & insured. Bilingual EN/ES. 24/7. Call (815) 212-7662.

Furnace RepairHVAC MaintenanceEmergency HVAC