Your furnace keeps your home warm and comfortable all year round, regardless of whether it’s gas or electric. When it works correctly, it provides an environment that is relatively warm and cozy. However, heating systems can and do malfunction, which creates bigger problems. In this article, we’ll discuss some common reasons your furnace might be blowing cold air and what to do about it.

Your HVAC system is what heats and cools your home. It consists of many parts, and these parts determine how well the system works at any given time. If any one of these important parts fails, it can cause the whole system not to work. You will either get cold air blowing from the vents or no air at all. To fix it, you will need to understand what each part does and how to check if it’s working properly. If you have any questions or need help, contact a qualified HVAC technician.

1. Dirty Air Filter

A dirty air filter can mess with your furnace big time. Air filters trap dust, dirt, pollen, and other particles from the air preventing these particles from entering the heating or cooling system and clogging the motor.

When filters get clogged with dust, it blocks the airflow, causing the furnace to overheat. As a result, it trips a safety switch which shuts off everything but the fan. Make sure to swap out those filters regularly to keep things running smoothly! You can buy these in bulk at your local hardware store.

2. Low Gas Supply

Your furnace may use gas as a fuel source. It needs a steady supply to create the flames that warm the air. When the thermostat signals the start of a cycle, the gas valve opens, allowing the gas to flow to the burners. The burners then ignite, creating a flame that heats the air.

When there’s not enough gas, the burners can’t generate sufficient heat. It’s similar to your stove. You can’t properly cook a steak with the flame turned down to a flicker. Keeping a steady gas supply ensures your furnace keeps providing warmth to your home!

3. Leaky Ductwork

Ducts are channels that carry the warm air from your furnace throughout your home. Typically made of metal or flexible plastic, ducts snake through walls, ceilings, and floors, ensuring every room gets its fair share of warmth. Over time, they can develop holes or separations that can allow warm air to escape. Regular checks for leaks and proper insulation keep your ductwork in top shape, making sure that comforting heat reaches every nook and cranny.

4. Damaged Pilot Light

In a furnace, the pilot light is like the spark plug in a car. It’s what ignites the flame. If it’s damaged or goes out, your furnace won’t produce heat. It’s like trying to start a car with a faulty ignition. If there is no pilot light, you’ll need to relight it or call a technician to relight it for you. A steady, well-lit pilot light ensures your furnace keeps working to keep you warm.

5. Faulty Thermostat

The thermostat is what tells your furnace when to kick in and how much heat to dish out. If it’s acting up or is on the wrong settings, your furnace might not get the message to warm things up. It’s like having a conductor who’s out of sync with the orchestra.

Check the thermostat settings, change the batteries, and ensure it’s not blocked by anything messing with its sensors. If issues persist, a replacement might be in order. A happy, accurate thermostat ensures your furnace plays the right tune for a cozy home!

6. Faulty Control Board

The control board is like the brain of your furnace, orchestrating all the functions. If it’s faulty, it might send wrong signals or fail to coordinate, leading to inconsistent heating. To troubleshoot, check for any visibly damaged components on the control board.

If you spot issues or if your furnace is acting wonky, it’s time to call in an expert to diagnose and possibly replace the control board. A smoothly operating control board ensures your furnace follows the right instructions for a comfortable home!

7. Clogged Flame Sensors

Flame sensors keep an eye on the burner flame. These little devices are positioned near the burners and keep a watchful eye on the system. Their job is to ensure there’s a steady flame burning. If they detect that the flame has gone out or is weak, they send a signal to the furnace’s control board to shut things down, preventing safety hazards like gas leaks. Verifying that those sensors are clear of dust and dirt ensures your furnace can “see” the flame and keep the warmth flowing!

8. Damaged Thermocouple

This tiny device is positioned near the pilot light and acts as a safety feature. Its main job is to sense the heat from the pilot flame. When it senses that the pilot flame is burning properly, it generates a small voltage. This voltage is what keeps the gas valve open.

If the thermocouple doesn’t sense enough heat, it doesn’t generate enough voltage, and the gas valve closes as a safety measure. To troubleshoot, check for visible damage or displacement of the thermocouple. If you spot issues, it might need replacement.

9. Condensate Line Blockage

A furnace operating properly generates water vapor as a byproduct. This moisture needs a way out, and that’s where the condensate line comes in. It carries this water outside your home, usually through a PVC pipe. If the condensate line gets blocked, the water can’t flow out, leading to a backup.

To prevent potential water damage, modern furnaces have safety mechanisms that shut down the system when a blockage is detected. Locate the condensate line (often a PVC pipe) and check for any obstructions. Clear them out, and you’ll keep that water flowing smoothly, ensuring your furnace provides sufficient warmth!

10. Fan Set to “On” Instead of “Auto”

When set to “On,” the fan runs continuously, even when the furnace isn’t actively heating. It’s like leaving a ceiling fan on all the time — it stirs the air but doesn’t necessarily warm it up. Switching to “Auto” means the fan only runs when the furnace is actively heating. It ensures the warm air circulates when needed, making your home cozier without unnecessary fan operation. Adjusting this setting can make a real difference in energy efficiency!

Call a Professional for Help

Heating systems can be tricky, and some issues are best left to the experts. If your furnace is still giving you the cold shoulder after trying the suggested solutions, it’s a clear sign to call in a professional HVAC technician from Honest Air Conditioning.

We possess the expertise to identify and address intricate issues, ensuring your furnace receives the tender loving care it deserves. Whether the issue is installation, repair, or maintenance, we excel in meeting all your heating, cooling, and indoor air quality needs. With years of dedicated service to residents in the Greater East Valley, our team of experts is committed to keeping you warm and comfortable. At the end of the day, achieving a cozy home sometimes demands the hands-on expertise of a seasoned professional!

Contact us at Honest Air Conditioning today for furnace repair in Mesa!