Chicago Furnace Repair Guide: What to Do When Your Heat Stops Working

Few things are more stressful than a furnace that suddenly stops working during a Chicago winter. With temperatures frequently dropping into the single digits or below zero, losing heat isn’t just uncomfortable—it can quickly become dangerous. The good news is that many no-heat situations are caused by simple issues that can be identified and resolved with a few quick checks. In many cases, a furnace shutting off doesn’t mean the entire system has failed.

In Chicago homes, everything from low thermostat batteries to tripped breakers or dirty flame sensors can trigger a furnace shutdown. Homeowners should begin by checking the thermostat to ensure it is set to Heat, the set temperature is higher than the room temperature, and the batteries aren’t dead. A blank or flickering thermostat screen is often a sign of a battery issue. Next, verify that the furnace switch—which looks like a wall light switch near the unit—is turned on, and that no circuit breakers have tripped. The furnace blower door should also be securely closed, since many systems won’t operate if the panel is loose. The air filter should be inspected as well; if it is heavily clogged, the furnace may overheat and shut down for safety reasons. During Chicago winters, filters often need to be replaced more frequently since the furnace runs nearly nonstop.

If the system still doesn’t turn on, check the outdoor furnace intake and exhaust pipes for snow or ice buildup. These pipes frequently become blocked after storms, causing the furnace to shut off automatically. If none of these DIY steps resolve the issue, the problem is likely mechanical. In the Chicago area, the most common winter furnace failures involve dirty or failing flame sensors, cracked or malfunctioning ignitors, blower motor problems, faulty limit switches, frozen condensate lines, and, in older systems, cracked heat exchangers.

Chicago’s combination of extreme cold, long heating seasons, and older residential buildings makes mechanical breakdowns more common than in warmer states. Homeowners should call a professional immediately if the furnace is completely unresponsive, blowing cold air, short-cycling, producing burning smells, or triggering carbon monoxide alarms. Fast action is especially important if elderly residents, young children, or pets are in the home. Typical furnace repair costs in Chicagoland range from $100–$200 for flame sensor cleaning, $150–$350 for ignitor replacements, $300–$900 for blower motor repairs, and $1,200–$2,000 for heat exchanger repairs. Emergency service may cost more during extreme cold snaps. Preventing future breakdowns is possible through regular maintenance, timely filter replacements, annual tune-ups, sealing air leaks, and ensuring the furnace is properly sized for the home.

Losing heat in winter is overwhelming, but most furnace issues are fixable when addressed quickly. Planz Heating & Air provides fast, dependable furnace repair throughout the Chicago area to restore heat safely and efficiently so homeowners can stay warm throughout the winter.