Home comfort · Fall maintenance
Before You Turn On the Furnace: A Fall Checklist for Chicago Homeowners
The first cold evening is an inconvenient time to discover that the heat will not start. A short fall check gives you time to notice a problem, find your equipment information and arrange service before your home depends on the furnace every day.
Start with four things: the thermostat, the correct filter, clear air vents and working carbon monoxide alarms. Then arrange a professional heating inspection. A furnace that produces warm air has passed a basic comfort check; that alone does not confirm that its combustion and safety systems are working correctly.
This checklist is for a forced-air furnace. If your home uses a boiler, radiators or a heat pump, follow that system’s manual: its controls, maintenance and normal operating behavior can differ.
1. Check the thermostat before changing anything else
Review the display, heating mode and programmed schedule. A summer setting, an old vacation schedule or a low-battery warning can explain why the house is not warming when you expect it to. If your thermostat uses replaceable batteries, follow its instructions.
On a mild day when you can stay home, select Heat and set a comfortable temperature above the displayed room temperature. Observe a normal heating cycle using only the regular controls. Note whether the system starts, delivers warm air and reaches the setting. Allow for the normal startup sequence described in your manual.
If nothing happens, or the furnace repeatedly starts and stops without warming the house, record what you see. Avoid repeated resets or removing panels to investigate. Carrier’s troubleshooting guide identifies thermostat settings, restricted airflow and repeated cycling as useful starting points for diagnosis.
2. Give the filter a proper check
A filter can be easy to forget during the change from cooling to heating. Check the homeowner-accessible filter following the equipment’s shutdown and replacement instructions. Match the specified size and type, and follow the airflow-direction marking. If access is unclear or requires opening a service compartment, ask a technician to show you.
Follow the manufacturer’s replacement schedule and inspect the filter between changes; do not assume every filter lasts the same number of months. Keep the package or take a photo of the label so the next replacement is easy to identify. Do not wash a disposable filter or operate the system without its required filter.
ENERGY STAR recommends regular filter checks and annual professional preseason maintenance. A fresh filter supports airflow, but it does not replace an inspection.
3. Walk through the rooms, not just the utility area
Look for furniture, rugs and curtains covering supply registers or return grilles. These openings serve different jobs: one delivers conditioned air, while the other lets air return to the system. Both need a clear path. Keep storage away from the furnace and respect the clearances in its manual.
If one room was uncomfortable last winter, write that down now. “The upstairs bedroom stays cold while the living room reaches the thermostat setting” is a more useful service description than “the heat is weak.” Include whether the problem affects one room, one floor or the entire home. Carrier’s maintenance guidance also emphasizes clear vents and space around the equipment.
4. Make the safety checks part of the routine
Test carbon monoxide alarms according to their instructions and check their replacement dates. The U.S. Consumer Product Safety Commission recommends CO alarms on every level and outside sleeping areas. Carbon monoxide has no smell, so a lack of odor does not establish that the air is safe.
Leave immediately if a CO alarm sounds or you suspect a gas leak. Call 911 from a safe location; for a suspected gas leak, also call your gas utility. Do not use switches or a phone inside the suspected leak area, and do not search for the source yourself. Follow emergency responders’ directions before returning. See Nicor Gas’s leak-response guidance.
5. Know what the professional visit should resolve
A homeowner checklist cannot inspect a heat exchanger or evaluate combustion. Ask what the appointment includes. ENERGY STAR’s heating checklist calls for professional checks of fuel connections, gas pressure, burner combustion, the heat exchanger and operating controls.
Prepare the model number if it is safely visible, the last service date, any displayed error code and a short description of the symptoms. Mention new noises, persistent unusual odors, water around the unit or repeated shutdowns. Do not relight a pilot, adjust gas components or bypass a safety switch as part of a fall check.
Need help before the cold weather?
Alan Appliance Repair handles appliance and HVAC service. Tell us your furnace type, symptoms and location so we can discuss the next step.
Call (224) 347-6861 Explore furnace serviceService requests are accepted 24/7. Technician visits are by appointment and subject to availability. For gas or CO emergencies, contact emergency services first.
