Why My Modine Garage Heater Blowing Cold Air [Solved]

The issue of the Modine garage heater blowing cold air typically occurs when the heater overheats and trips the manual reset control on its own for safety purposes.

Now, this issue can be solved immediately and easily by reconnecting the heater and pressing the manual reset button. 

However, this is just one reason for the Modine garage heater not blowing hot air. There are quite a few other instances that cause the garage heater to blow cold air instead of hot air. 

modine garage heater blowing cold air

Among these issues, clogged air filters, gas leakage, faulty components, and loose wiring cause the most trouble. Keep on reading to know how these issues affect the Modine garage heater and how to work on these problems easily. 

Why Modine Garage Heater Blowing Cold Air [Reasons + Solutions]

Here are the most common reasons why the Modine garage heater does not blow hot air and their simple solutions:

Note: You can also read how to fix Mr Heater’s Big Maxx problems.

1. Clogged Air Filters

Clogged air filters are one of the reasons why the Modine garage heater won’t ignite. Over time, dirt and dust particles accumulate in the filters and create a blockage that causes a disruption in the path of the warm air.


Clean the air filters properly to get rid of all the dirt and dust particles. This will remove the blockage and stop the cold air from blowing out of the heater, replacing it with warm air. To prevent this, make sure that you maintain an air filter cleaning schedule.

2. Overheating

Garage heaters often overheat due to operating for a long period of time or excessive temperature settings.

In cases like these, the Modine garage heater trips the manual reset control as a safety procedure. This causes a breakdown between the circuit which in turn results in the Modine heater not blowing hot air.


If the manual reset control has been tripped as a safety procedure, the garage heater will not start working or dissipating heat until you reset the system.

However, it is an easy process and all you need to do is disconnect the connection for a second and reconnect it and then push the manual reset control button.

3. Vent Leakage

Another common reason behind the garage heater not blowing warm air is that there could be a leakage in the vent of the heater.

This leakage causes the warm air to escape easily through the vent, causing the garage heater fan blows cold air into the room.


Check the vent properly and identify where the leakage is located. Seal all the leakages properly with tape or other permanent means to fix the issue.

Once all the leaks are completely covered, the warm air cannot escape and will heat up the garage.

4. Loose Wiring

There are often instances when the wires to the garage heater loosen by accident or on their own, causing the heating element to lose connection with the heater.

This causes the fan to operate when the heater is switched on but the heating element fails to establish a proper connection. Thus, the Modine garage heater blows cold air instead of hot. 


Conduct a proper check of the wiring in the heater and make sure that all the wires are properly connected in their respective places.

If you notice any loose wiring, then repair it, and Voila! Your heater will start blowing hot air once again.

However, if you are not an expert in fixing wiring shocks then it can often result in an accident. To ensure your safety, we recommend that you seek the assistance of a professional in cases like these.

5. Faulty Heating Element

Another major reason behind the Modine garage heater not blowing hot air is a faulty heating element.

These elements are electrical components and can often stop working due to internal issues and so on. However, this faulty heating element will prevent the heater from working and cause cold air to come out of the heater.


Check all the heating elements of the heater and make sure that all the components are working properly and in proper shape.

Identify the faulty element and repair or replace it, depending on the situation.

However, similar to the previous solution mentioned above, we suggest seeking help from a professional if you cannot identify the issue or have trouble mending the element.


Why is my Modine heater not working?

There are quite a few reasons that can prevent your Modine heater from working properly. These include faulty elements, loose wiring, vent leakages, overheating, and many more.  

Can I fix my Modine heater on my own?

Yes, you can easily fix your Modine garage heater on your own. Simply identify why the heater is blowing cold air and take the necessary steps to fix it.

How long does a Modine garage heater last?

A Modine garage last will last for about 15 to 20 years on average. However, you will have to take care of the heater and clean it from time to time.

How do I troubleshoot the manual reset control?

To troubleshoot the manual reset control, unplug the heater for a few seconds and plug it back. Press the manual reset limit button and the heater will start working.


Now you know why your Modine garage heater blowing cold air and how to fix them. So, from now you can now bring your garage heater back to life by yourself by following our guide without any trouble.

But don’t forget to let us know in the comment box if you still are struggling with the issue or with any other issue with your heater. We will be glad to help you.  

About William

William is the founder of Fireplacehubs.com. He has real life practical skills in fixing smoker & heating appliance issues. He loves to share his knowledge & helps others in fixing their appliances & saving their money. William firmly believes that anyone can repair his or her unit with the correct guidance & knowledge. See more at about us.

Leave a Comment