How to Fix Car Heater Blowing Cold Air

Once a vehicle’s car heater starts blowing cold air instead of hot air then there’s a problem with the car heating system.

A car heater’s main purpose is to introduce warmth (hot air) into the car when there’s excess cold introduced by the air conditioner.

Likewise, the air conditioner helps make the cabin chilled out and prevents excess heat.

If one of these systems works interchangeably or fails at any point while driving then the driver (and passenger) would experience extreme discomfort.

Your vehicle can also blow cold air while idling, when stopped, or intermittently

The problem is likely caused by a faulty cooling system, low engine coolant level, a faulty thermostat, and others that’ll be discussed below.

Additionally, a car heater blowing cold air can be fixed by refiling the coolant, getting a thermostat replacement, or getting a new heater control, amongst others

In this article, I’ll show you possible reasons why your car heater is blowing cold air and how to fix it.

Why is My Car Heater Blowing Cold Air

A car heater blowing cold air Is a minor issue since it is easy to diagnose and repair.

For those who don’t know, here are possible reasons why your car heater is blowing cold air instead.

1. Low Engine Coolant Level

Engine coolant does more than keeping the engine running at its usual operating temperature. Also, it is crucial for the heating system’s proper heat support. If the coolant level is below the recommended level, the heater air vents will blast chilly air.

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2. A Problematic Thermostat

The main function of a thermostat in a vehicle is to ensure that the engine reaches the recommended temperature as soon as possible and also helps maintain the temperature.

If the engine fails to reach its optimal temperature then your car heater might blow colder than usual.

3. Air in the Heating System

If air goes into the heating system due to a component change then your car heater might blow cold due to the leakage.

4. Damaged heater control

Since these components are controlled by buttons and controls, it may be possible that the heater control is faulty and would need repair.

Also, it could be that the button is frozen and as such, making you think that the car heater isn’t functional.

5. Spoilt Heater Flaps

There are flaps that control the flow of hot or cold air into the vehicle. Any damage to these components will bring up an error code to your check engine light.

6. Bad Heater Core

The heater core controls the car’s heating system and as such any defects that occur to it will affect the overall functioning of the heating system.

Car Heater Blowing Cold Air – FIX

We’ve seen the possible reasons why a vehicle heater will blow cold air, let’s see how to Fix the cooling system issue.

1. Refill the Coolant

When the heater blows cold air, the first thing you must check is the coolant level.

While your car is parked and cool, open the radiator cap to see the coolant level. Make sure that the coolant is filled to the edge.

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Also, Make that the coolant level in the reservoir tank is within the specified range. There are MIN and MAX levels in the reservoir tank. Fill the tank up till the MAX line is reached. Overfilling or underfilling will result in problems. So, do that according to moderation.

2. Heater Control Replacement

If you notice that the fault is from your heater control then you can seek the service of an auto engineer to get it fixed.

You can also purchase a heater control from amazon then proceed to follow YouTube guides in fixing it yourself.

3. Replace problematic Thermostat

If you notice the fault is from your thermostat after testing and diagnosing it then you can initiate a replacement.

4. Remove blockage in the Heater core

Examine the heater core if you think that’s what’s wrong. The issue can be resolved by cleaning the exterior of a blocked heater core manually, flushing the heater core pipes, and removing any dirt that contributed to the issue. In some circumstances, you might need to buy a new heater core.

5. Heater Flaps Replacement

Also, inspect the heater flaps or blend doors and perform a replacement if possible

6. Bleed the cooling system

Bleed the entire cooling system to get rid of any air that may be trapped there or airlocks. The procedure can be challenging, especially if you’re a novice. Therefore, it is preferable to have a skilled mechanic release the trapped air.

7. Use the Windows

If you can’t implement any of the above fixes then you should consider winding up the windows while driving to prevent air from coming in thereby releasing heat into the car.

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Do this while the Air conditioner is turned off though.

Car Heater Blowing Cold Air Cost To Fix

Because a number of things can be the cause of a car heater blowing cold air, it is challenging to estimate the repair cost. However, the price of repairs can range from $10 to $1,000 or even more.


Can I Heat My Car Without a Heater?

Yes, Without a heater, there are other inventive and economical methods to keep your car warm but you can compare it to that of a car heater.

Alternatives such as the use of blankets, hand warmers, covering the windshield when idle, or setting up a heated seat can be used to generate heat in a car.


A car heater blowing cold air Is a minor issue but at the same time, it could cause discomfort to car owners especially those who frequently make use of the cooling system.

In this article, I’ve outlined all the possible reasons why a car heater will blow cold and ways to fix them.

However, if you’re inexperienced and can’t fix your car yourself using the above guide then it’s advisable to call the attention of a mechanic.