8 Reasons Why Your Electric Furnace is Blowing Cold Air

Are you feeling the cold shoulder from your electric furnace? Is it leaving you shivering as it blows cold air instead of the expected warm comfort? In the heart of the heating season, a furnace blowing cold air is a distressing problem.

As an HVAC enthusiast, I’m here to guide you through several reasons why this might be happening and how to fix these issues. So let’s get right into it.

8 Reasons Why Your Electric Furnace is Blowing Cold Air

1. Thermostat Settings

Your thermostat settings could be causing your furnace to blow cold air. The fan setting might be set to ‘ON’ instead of ‘AUTO’, causing the fan to blow air even when the heating elements are not active.

Ensure your thermostat fan setting is on ‘AUTO’ to fix this issue.

2. Dirty Air Filter

A dirty air filter can limit the airflow to the heating elements, causing the furnace to overheat and triggering a safety feature that shuts off the elements while keeping the fan running. Replacing or cleaning your furnace filters could resolve this problem.

3. Tripped Circuit Breaker

Your electric furnace has separate circuit breakers for the blower fan and the heating elements in your circuit breaker box.

If the breaker for the heating elements is tripped, only the blower will work, blowing cold air. Resetting the circuit breaker should fix this issue.

4. Broken Heating Elements

The heating elements in your electric furnace may be broken or burnt out. If this is the case, the blower will blow air over the non-functioning elements, resulting in cold air. A furnace repair by an HVAC professional is required in this case.

5. Overheated Furnace

An overheated furnace could be another reason for cold air. This usually occurs due to a dirty filter or blocked air vents.

A safety feature will shut off the heat to prevent damage, but the blower fan will continue to run. Replacing the dirty filter or unblocking the vents should resolve this issue.

6. Faulty Thermostat

A malfunctioning thermostat might be failing to signal the furnace to heat the air. Replacing the thermostat or contacting a furnace technician for a more complex diagnosis might be necessary.

7. Furnace Size

If your furnace is too small for your space, it might not be able to heat your home efficiently. In this case, you might need to upgrade your furnace to a size appropriate for your home.

8. Ductwork Issues

Air leaks or poor insulation in your air ducts could cause the warm air to cool down before it reaches the supply vents. Inspecting the ductwork for leaks or poor insulation can identify this problem.

If found, it should be addressed by a professional.

Why is My Furnace Blowing Cold Air and Won’t Shut Off?

If your furnace is blowing cold air and won’t shut off, it might be due to a faulty thermostat, specifically a malfunctioning thermostat fan setting.

Try adjusting the fan setting to ‘AUTO’. If this doesn’t work, call an HVAC professional for an inspection and potential thermostat replacement.

Why is My Furnace Blowing Cold Air Only at Night?

This could be due to the temperature setting on your thermostat. At night, as indoor temperatures drop, your furnace might struggle to keep up if it’s not sized correctly for your home.

Ensure your furnace is properly sized and that your thermostat is set to an appropriate temperature for the evening hours.


Several factors can cause your electric furnace to blow cold air, ranging from simple issues like improper thermostat settings to more complex issues like faulty heating elements or ductwork problems.

Regular furnace tune-ups and maintenance by heating experts can prevent most of these issues, ensuring your central heating system runs smoothly throughout the heating season. But remember, when in doubt, always reach out to a furnace technician to ensure the safety and efficiency of your heating systems.

About Roy Cohen

Roy Cohen has a burning passion for heating, cooling, and ventilation. He aims to help you save money on expensive repairs and bring you the best HVAC products. He has years of experience behind him in HVAC repair and garage maintenance.

You can find Roy at his LinkedIn or his email: [email protected]

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