Why Is My Furnace Blowing Cold Air?
If you’re wondering, “Why is my furnace blowing cold air?” a few common problems could be causing it. The issue may be as simple as an incorrect thermostat setting or a dirty air filter. More serious problems can involve the ignition system or another furnace component. Understanding the possible causes can help you decide what to check yourself. It can also help you decide when you should schedule professional furnace repair services.
Check Your Thermostat Settings First
Before assuming something is wrong with your furnace, check the thermostat settings. Make sure the system is set to “heat,” and the temperature is higher than your current room temperature. Also check the fan setting. If the fan is in the “on” position, it will keep running even when the furnace stops heating.
That can make it seem like you have an issue with cold air from a furnace. The blower may simply be circulating room temperature air between heating cycles. Setting the fan to auto makes it run only when the furnace heats.
Clogged Air Filters and Overheating Protection
A dirty air filter can restrict the airflow moving through your furnace. When air can’t circulate correctly, the heat exchanger heats up. Your furnace has a high-limit safety switch that helps protect the system from overheating.
If the temperature gets too high, the switch will shut off the burners. The blower may continue running to cool the furnace. If this happens, you may notice cold air from the vents even though the blower is still running.
Check your filter regularly and replace it when it becomes dirty. A clogged filter can also reduce system efficiency and cause other furnace problems. It’s also important to seek annual furnace maintenance to take care of your system.
Pilot Light and Electronic Igniter Issues
Older furnaces may use a pilot light to ignite the gas burners. If the pilot light goes out, the burners can’t produce heat. You might feel cold air coming through the vents.
Many newer furnaces use an electronic igniter instead. A failing igniter may prevent the burners from lighting when the furnace begins the heating cycle. Other ignition problems can cause similar issues.
If you think you have an ignition problem, avoid attempting to repair the system yourself. Gas and ignition problems can create serious safety risks if you don’t handle them correctly. A qualified technician can determine why the furnace isn’t working and make the correct repairs.
Ductwork Leaks and Gas Supply Problems
Problems with your ductwork can also affect the temperature of the air coming out of your vents. Unsealed ducts in a cold basement or crawl space pull chilled air into the system. That can make the air from your furnace feel colder than usual.
Gas supply problems can also prevent your furnace from producing heat. A closed gas valve or an interruption in the gas supply can stop the burners from lighting. If you suspect a gas supply problem, do not attempt the repairs yourself. A technician will inspect the system and find what is causing the lack of heat.
Simple Troubleshooting Steps to Try Before Calling
You can check a few basic settings before scheduling service. These simple checks may help identify an obvious cause without opening the furnace.
Start with these basic checks:
- Replace a dirty or clogged air filter
- Confirm the thermostat is set to HEAT and AUTO
- Make sure the thermostat is set above room temperature
- Check whether you have a tripped furnace breaker
Do not open the furnace or attempt to repair gas, electrical, or ignition components. Professionals must safely diagnose and repair those problems.
When to Call Sal’s Heating & Cooling for Professional Repair
Some furnace problems need more than basic troubleshooting. If your furnace continues blowing cold air after you check the thermostat and replace a dirty filter, the problem may require professional attention.
Short cycling can indicate an airflow problem, overheating, or another issue that needs professional attention. Persistent ignition failures can also prevent the furnace from producing heat. Unusual noises, repeated shutdowns, or a furnace that can’t maintain the set temperature are other signs that you may need to schedule furnace troubleshooting and repair services.
Our team can inspect the system and determine why it’s not heating properly. Then, our professional furnace repair services can address the underlying problem and help restore reliable heat.
If you are dealing with a furnace blowing cold air, contact us at Sal’s Heating & Cooling in Cleveland and throughout Northeast Ohio to schedule service and get your home’s heat working properly again.
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