The last thing a Lake Zurich, IL homeowner wants in winter is a furnace that’s blowing cold air. Why would a furnace do that? Well, there are three common reasons. The good news is that you can probably fix these problems all by yourself.

The Thermostat Is Set To “On”

When the thermostat is in the “On” position, the blower will continue to blow air whether that air has been heated or not. To rectify the problem, simply set the thermostat to “Auto.” With this setting, your heater will blow warm air only.

Your Furnace Has Gotten Too Hot

If your furnace has overheated, it was previously blowing hot air just like it should. But then it started blowing cold air, and after that, it blew no air at all. The most likely scenario is that your heating system got too hot. When that happened, something called the limit switch shut down the burners. This is a heating safety device designed to prevent overheating. When the burners are off, the blower blows cold air to cool off the furnace and restore it to safety.

Why do furnaces overheat? It could be due to lack of heater maintenance. Usually, a clogged air filter that restricts airflow is the culprit. A dirty filter can make your heating system work so hard that it overheats. Check your air filter; if it’s dirty, replace it. Your heater should now be working as it should.

Your Furnace Pilot Light Has Gone Out

If your pilot light has gone out, relight it. If all is well, it will stay lit. If it won’t relight, check to see whether the gas valve switch is in the “On” position. If it is, the pilot may be dirty and clogged. Clean it off so the gas can resume its flow. If the pilot lights but won’t stay lit, a copper rod called the thermocouple needs adjustment or replacement. This is a quick fix, but only if you know what you’re doing. If you’re not sure, schedule furnace repair.

To learn more about how to fix a furnace that’s blowing cold air, check out these tips from Martin Enterprises Heating And Air Conditioning or call 847-719-8442.