Why Is My Furnace Blowing Cold Air?

ccc • November 30, 2021

Furnace problems are never welcome. A furnace that has stopped working or is blowing cold air is frustratingly inconvenient.

 

A lot of things can cause your furnace to behave strangely. This blog will look at some of the most common furnace problems , how you can troubleshoot them, and what you can do to fix them.

 

 

Check the Thermostat

 

 

Your thermostat determines the temperature in your home and configures your furnace to reach the desired room temperature. Sometimes your thermostat can be set incorrectly, which will cause your furnace to blow cold air.

 

 

Check to see if your thermostat is set to heat. If it’s set to cool, that may be the problem. You’ll also want to make sure that your thermostat is set to “Auto” and not “On.” The auto setting configures your fan to stop blowing when the desired temperature is reached. 

 

 

If it’s set to on, this will keep the fan running even when the furnace is off, which means it’ll be blowing cold air.

 

 

The Furnace Isn’t Warmed Up

 

 

If you notice your furnace blowing cold air, it could simply need more time to warm up. Some furnaces need upwards of 15 minutes to reach maximum potential. This could also be the case on colder days when the outside air temperature dips below 30 degrees Fahrenheit. 

 

 

Give your furnace time to warm up for at least 15 minutes. If your furnace is still blowing cold air after 15 minutes, call a professional to diagnose the problem.

 

 

The Filter Is Dirty

 

 

The air filter from your heating and cooling system will catch dust, dirt, and debris. If your air filter is clogged, it can limit airflow to your furnace, which can cause it to overheat and shut off.

 

Be sure to check your filter regularly for any dirt or damage. If your furnace is blowing cold air, check the furnace to see if debris are caught in it. If there are, replacing your air filter should get warm air blowing again.

 

 

Condensate Lines Are Clogged

 

 

Condensate lines move water condensation away from your furnace. If there’s water present near the igniter, it will cause an ignition failure, which could cause your furnace to blow cold air. 

 

 

Your condensate lines can clog due to mold or other debris. Make sure to drain the condensate lines. If this seems like too much for you to handle, call a professional HVAC technician and have them take a look at the problem.

 

 

Check Your Ducts for Damage

 

 

Make sure to check your ductwork. If there is damage to your ductwork , this could cause warm air to escape, which will leave some rooms with cold air. This could be due to the age of your system, which can rust over time, or it could be from small rodents or other animals chewing through the ducts.

 

 

Make sure to inspect the ducts for any holes or damage. You can seal damaged ducts with tape or replace the damaged sections.

 

 

Check the Gas Supply

 

 

If your furnace runs on gas and is blowing cold air, check the gas lines or supply. You may be running low on gas, which means the pilot light keeps going out. Or, you may have damage to the gas line that supplies your furnace. 

 

 

The good news is that if there’s a fault with the gas supply, your furnace will automatically shut off. Have a professional check the gas lines and the gas supply for any problems.

 

 

Furnace Is Overheating

 

 

Most modern furnaces have safety features to prevent severe damage or disasters from happening. If your furnace is not working correctly, it will shut down on its own. Here are the main reasons why a furnace can overheat and shut off.

 

 

Mechanical Failure

 

 

Furnaces have many moving parts in order for them to operate. If one of these moving parts fails, it can make your furnace run harder, which can ultimately cause it to overheat. If you believe your furnace is failing due to a mechanical issue, have a professional HVAC technician inspect your furnace for any problems.

 

 

Clogged Filter

 

 

A clogged filter is one of the more common furnace problems. When your air filter is clogged, your furnace will be working harder than expected. If it runs too hard, it can potentially overheat and shut down on its own. 

 

 

Preventative maintenance is critical for your furnace to run optimally. Depending on the manufacturer’s recommendations, be sure to inspect and replace your air filter every 3-6 months. Doing this can prevent thousands of dollars in repair.

 

 

Age

 

 

Even with the best preventative maintenance schedule, your furnace can still overheat due to age-related internal failures. Age will lead to corrosion or worn parts. Over time, your furnace will need parts replaced to keep it running correctly. 

 

 

If this happens, you’ll have to ask yourself what the most cost-effective route to take is when it comes to your furnace issues. Failing internal parts in your furnace can range from a couple hundred dollars to several thousand dollars. 

 

 

If that’s the case, you may want to replace the entire furnace rather than have it repaired.

 

What to Do if It’s Still Blowing Cold Air

 

 

There’s nothing worse than a furnace blowing cold air on a cold night. The best thing is to look over all the tips we’ve gone over and diagnose the problem accordingly. 

 

 

Addressing these issues first will most likely solve your problems. If you’ve addressed all of these common furnace issues and you’re still having problems, you’ll need to reach out to an HVAC company and they can help. 

 

 

We specialize in all heating systems such as furnaces, heat pumps, and geothermal heating .

 

Give us a call and one of our technicians can help you out right away!

January 22, 2025
As the winter season approaches in Charleston, South Carolina, it’s time to ensure your HVAC system is ready to keep your home warm and comfortable. While winters here are generally mild, the occasional cold snap can put your heating system to the test. At Carolina Climate Control, we want to help you prepare your HVAC system for the season ahead with these essential tips. 1. Schedule a Professional Maintenance Check Before winter fully sets in, schedule a maintenance visit with our experienced technicians. Regular maintenance helps identify potential issues before they become costly repairs. During the checkup, we’ll inspect your system, clean components, and ensure everything is operating efficiently. 2. Replace or Clean Your Air Filters Clean air filters are vital for efficient HVAC performance. Dirty filters can restrict airflow, forcing your system to work harder and increasing energy costs. Replace or clean your filters monthly, especially during periods of heavy use. 3. Test Your Thermostat Ensure your thermostat is working properly and set to your desired temperature. If you’re still using a manual thermostat, consider upgrading to a programmable or smart thermostat for better temperature control and energy savings. 4. Inspect Your Ductwork Leaky or poorly insulated ductwork can lead to significant heat loss, making it harder for your HVAC system to maintain a consistent temperature. A professional inspection can identify and seal any leaks, ensuring your system operates efficiently. 5. Check Your Insulation Good insulation keeps warm air inside and cold air out. Inspect your home’s insulation, especially in the attic and around windows and doors. Adding weather stripping or caulking can make a big difference in maintaining indoor comfort. 6. Clear the Area Around Your HVAC System Make sure your outdoor unit is free of debris such as leaves, dirt, and branches. A clean unit operates more efficiently and is less likely to experience issues during the colder months. 7. Be Prepared for Emergencies Charleston winters can bring unexpected weather changes. Make sure you have a plan in place for power outages and other emergencies. Keep blankets, portable heaters, and emergency contact numbers on hand, including our 24/7 service line for urgent HVAC repairs. 8. Consider Upgrading Your System If your HVAC system is more than 10-15 years old, it might be time to consider an upgrade. Modern systems are more energy-efficient and reliable, ensuring your home stays comfortable while lowering your utility bills. To learn more about some of the energy-efficient products we carry and install, check out some of our product pages . Trust Carolina Climate Control to Keep You Comfortable This Winter Preparing your HVAC system for winter doesn’t have to be stressful. Carolina Climate Control is here to help with expert maintenance, repairs, and installations tailored to Charleston’s unique climate. Contact us today to schedule your winter HVAC checkup and enjoy a warm, worry-free season.
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As the cooler months approach, Charleston homeowners are beginning to think about how to keep their homes warm and cozy without breaking the bank on energy bills. With a variety of energy-efficient heating options available today, it’s easier than ever to find a system that balances comfort and cost savings. At Carolina Climate Control, we’re here to help you explore the best solutions for your home this winter. 1. Heat Pumps: A Year-Round Solution Heat pumps are one of the most efficient heating options for Charleston’s mild winters. These systems work by transferring heat from the outside air into your home, using less energy compared to traditional heating methods. Many modern heat pumps also double as air conditioners, making them an excellent year-round investment. If you’re considering a heat pump, look for models with a high Heating Seasonal Performance Factor (HSPF) for maximum efficiency. And if you already have a heat pump, regular maintenance ensures it operates at peak performance. 2. Ductless Mini-Split Systems For homes without ductwork or those looking to heat specific areas, ductless mini-split systems are a fantastic choice. These systems allow for zoned heating, meaning you can heat only the rooms you’re using, reducing energy waste. They’re also quiet, compact, and highly efficient, making them a popular option for Charleston homeowners. 3. High-Efficiency Furnaces If you prefer a traditional furnace, upgrading to a high-efficiency model can make a significant difference in energy savings. Modern furnaces with an Annual Fuel Utilization Efficiency (AFUE) rating of 90% or higher convert most of the fuel they consume into heat, minimizing waste. Pairing your furnace with a programmable or smart thermostat can further enhance efficiency by allowing you to set heating schedules and avoid heating your home when no one is there. 4. Radiant Floor Heating While not as common, radiant floor heating is a luxurious and efficient way to keep your home warm. This system uses electric heating coils or water-heated tubing beneath your floors to provide even, consistent heat throughout a room. It’s especially appealing for homes with tile or hardwood flooring. Tips for Maximizing Efficiency Regardless of the heating system you choose, there are simple steps you can take to make your home more energy-efficient this winter: Seal Drafts: Check for air leaks around windows and doors and seal them with weatherstripping or caulk. Insulate: Proper insulation in your attic and walls helps retain heat. Maintain Your System: Schedule regular maintenance with Carolina Climate Control to ensure your heating system runs efficiently all season long. Find the Right Solution with Carolina Climate Control Choosing the best heating option for your Charleston home depends on your budget, home size, and personal preferences. At Carolina Climate Control, we specialize in helping homeowners find energy-efficient solutions that keep their homes comfortable and their energy bills manageable. This winter, don’t let high heating costs dampen your holiday spirit. Get in touch with us today to discover our energy-efficient heating solutions and schedule a consultation with our expert team. For more information on the energy-efficient heating equipment we offer and install, visit our products page . Stay warm, Charleston!
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