At one moment, your heating unit may be working correctly, then the next, you have a blast of cold air from your vents. This is one of the most frustrating experiences you can have during the cold months. The result is an uncomfortable home for you and your family. Even worse, cold temperatures can place physiological stresses on your body and cause other severe health problems, especially in older individuals.

Several reasons can make your heating system start blowing cold air instead of warm air. The problem can result from a simple error or a complex issue in one of the vital components in the furnace. Below are more in-depth details on what makes a furnace blow cold air.

1. Wrong Thermostat Setting

The thermostat determines your home’s heat requirements and sends instructions to the furnace on when to heat based on the room temperature. If you notice your furnace is blowing cold air, the first place to check should be your thermostat settings. When you set it an ‘ON,’ the system’s motor and blower fan work consistently even when the unit isn’t heating your house. The blower will send air through the ducts between heating cycles, but it won’t be hot because the furnace isn’t creating heat. Therefore, ensure the thermostat is set at ‘AUTO’ to enable the blower works when the heating system cycles. This way, you’ll have consistent warm air in your home as per your preference. If your furnace continues to blow cold air even after resetting the thermostat, call our team to check it out.

2. Overheating Furnace

Like other electrical appliances, your heating system can overheat. When this happens, a safety feature limits the temperatures emitted by your system and eventually shuts down the heating cycles. However, the furnace may temporarily blow cold air before the appliance eventually shuts off. A heating system may overheat due to a mechanical failure, especially if your equipment is 15 years or older. Dirt buildup within the unit is also a common cause of overheating. Always rely on an experienced professional to resolve overheating issues with your furnace. We have in-depth knowledge about heating systems, so we’ll diagnose and fix your equipment quickly.

3. Leaky Ductwork

Your heating system relies on ducts to send hot air into every space in your home. The heated air can escape if there are leaks, holes, or other damages in your ductwork. Also, unconditioned air from the attic and other areas in your ductwork can find its way into your house. As a result, the air coming from your vents may be warm or cold. If your furnace is working correctly, but the vents emit cold air, your heating system needs a professional assessment. Our team has state-of-the-art tools and equipment to assess your entire duct system, find any cracks or holes, and seal them.

4. Airflow Restrictions

Your furnace needs ample airflow to function correctly. If there are blockages within the appliance, vents, or ductwork, the furnace will struggle as it tries to supply enough heat into your house. Dirty filters are a common cause of airflow restriction in your appliance, which can eventually make your furnace start emitting cold air. The continued accumulation of debris in the air filter block airflow in the system’s heat exchanger, which can cause your system to overheat, leading to a shutdown in the long run. Regular checkups by our experienced technicians will determine when to clean or replace your appliance’s air filters to avoid this issue. Replacing air filters is also a critical safety measure to prevent a fire or other problems with your furnace.

5. Pilot Light Malfunction

If you have a gas furnace that’s about 20 years old, it likely has a pilot light that ignites the burners. If the ignitor fails or the pilot light goes out, the burner switches off, causing the furnace to emit cold air. This may be due to a strong draft or a dirt valve, mainly when your heating appliance stays idle for long periods during the summer. You can request our assistance to help you relight the pilot as per the manufacturer’s manual. If this doesn’t work, we will assess your equipment, do the necessary repairs, and ensure the pilot light works properly. For furnaces that use an ignitor, our technicians will replace the broken component.

6. Thermostat Working Incorrectly

Sometimes, you may notice that your furnace is inconsistent in maintaining your desired indoor temperatures. An incorrectly working thermostat may be the main reason for this issue because it’s sending the wrong signal. The fan may come on, but the burner isn’t working. You may experience this problem if your heating system isn’t installed by a qualified professional, or you have an old thermostat. The best solution is to call our technicians to replace your old thermostat.

7. Dirty Flame Sensor

Furnaces with a pilotless ignition rely on a flame sensor to ensure proper heat generation. The burner may shut off if the flame sensor or rod is covered with grime or dirt. Once the frame rod shuts down, it turns the cycles between cold and warm relatively quickly. Although the blower continues to run, the appliance will emit cold air because there is no heat production. We can help restore this issue by cleaning the flame sensor to restore the heating function. In some cases, we can recommend a replacement to avoid further malfunctions.

8. Gas Supply Problem

Using a gas furnace requires a steady gas supply for the burners to generate heat. When there is insufficient gas supply, your heating system won’t generate hot air, but the blower will still run, resulting in cold air. As a safety measure, the furnace will eventually shut off. The problem can result from inadequate gas in your tank or something preventing the gas from reaching your equipment. You can confirm if it’s a gas supply issue affecting your entire house by checking other gas appliances in your home, such as the range or gas oven. You should also check whether the gas valve is turned on by turning the valve in a parallel position with the gas pipe. If the furnace continues to produce cold air after the gas valve adjustment, seek our professional help.

Let the Right Professionals Fix Your Faulty Furnace

You cannot rely on a furnace that emits cold air to keep your home comfortable during winter. If your heating system has this problem, we have the best furnace repair professionals who can take care of any issue with your equipment. Alberta Mountain Air Heating and Air Conditioning has been assisting customers in resolving their heating problems since 2004. Throughout the years, we have consistently provided top-notch services to every client, no matter how big or small the task may seem. Our team always responds on time and restores your comfort levels in the shortest time possible. Our professionals also undergo continuous training to keep up with the industrial trends. Therefore, you can have peace of mind that you have the right professionals for the job. Our technicians perform AC repair, IAQ testing, heating maintenance, AC installation, remodeling, heating installation, and AC maintenance services in Calgary. Contact Alberta Mountain Air Heating and Air Conditioning to book a service with our professionals.

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