The temperature drops, you turn on the heat… and nothing. Only lukewarm air—or straight-up cold air—comes out of the vents. It’s one of the worst surprises when winter season arrives without warning.
Before you panic or spend hundreds of dollars on an emergency repair, let me show you the 5 most common reasons why your heating system isn’t working properly.
1. Your Filter is Dirty (And It’s the Easiest Fix)
Here’s the number one culprit: a clogged air filter. Your heating system has a filter that traps dust, dirt, and allergens. When it gets dirty, air can’t flow properly, and the system overheats and shuts off automatically as a safety measure.
The solution is simple: check your filter every month during winter. If it’s gray or brown, replace it. A new filter costs between $15 and $30 and takes less than 5 minutes to swap out. It’s the cheapest and most effective repair you can make.
2. Your Thermostat is Misconfigured
It sounds obvious, but it happens more often than you’d think. Make sure your thermostat is set to “heat” mode and not “cool” or “auto.” Also verify that the temperature setting is higher than your current indoor temperature.
If you have a programmable or smart thermostat, double-check that it’s programmed correctly for the season.
3. The Pilot Light is Out (Older Systems)
If you have a gas heater with a pilot light, that small flame needs to be lit for the system to work. If it went out, the system can’t start the combustion process.
How to relight it: Find the gas valve, switch it to “PILOT,” press the ignition button for 30 seconds, then switch back to “ON.” If the pilot light won’t stay lit, you likely need a professional repair.
4. You Have Air Leaks in Your Ductwork
A heating system that works perfectly but your house is still cold could mean air is escaping through leaks in the ducts. Warm air escapes before reaching your rooms, especially in uninsulated attics or basements.
This is a repair that requires a professional, but it’s a worthwhile investment that also lowers your energy bill.
5. Your System Needs Professional Maintenance
If you’ve checked everything above and nothing works, it’s time to call the experts. Your system might need a professional cleaning, refrigerant recharge, or has a damaged component like the expansion valve or compressor.
Prevention: The Best Remedy
Don’t wait until it’s too late. Before winter begins, schedule preventive maintenance. An annual inspection by a professional costs between $100 and $200, but it can save you thousands in emergency repairs.
At Any Appliance Repair Co., our certified technicians can inspect your system, clean components, and ensure it’s ready for winter. We offer same-day service, and there’s no charge for the initial visit if you proceed with repairs through us.