Car Heater Not Working – What Could Be Wrong? [Key Reasons Explored]

Imagine driving in your car in cold weather, and then the car heater suddenly malfunctions. That's why, in this article, we will discuss what causes the car's heater to stop working. We did plenty of research to figure out why this happens and will also discuss related questions.

There are many reasons your car's heater is not working. Luckily, most issues are not a worst-case scenario, and require maintenance, repairs, or replacement parts. Here are some key reasons your car's heater is not working. Review the following problems below:

  • Multiple damaged car parts are affecting the heater
  • The antifreeze levels are low
  • The blower fan is malfunctioning
  • The thermostat is bad
  • Engine problems are interfering with the car's climate controls
  • The radiator has a leak

Interested in learning more about what causes your car heater to fail? Continue reading as we cover the cost of repairs, diagnosing car problems, and the best climate control system on the market. You will also find interesting topics that we have previously written at the end of this article. 

Heater in deck of a car malfunctioning, Car Heater Not Working - What Could Be Wrong? [Key Reasons Explored]

My Heater Is Failing, What's Wrong?

A failing heater may be a sign that there are other car parts that are damaged, and that is affecting your heater's performance. Unlike a furnace in a home, different parts in a car work together to produce heat.

That is why a failing heater can be a real problem. It likely means that there is more than one damaged part in your car, and it is interfering with the car heater's function. 

Falling Antifreeze Levels

Refilling the antifreeze system

A sudden decrease in your coolant level can cause a vehicle's heater to fail. Keep in mind, antifreeze coolants do not easily evaporate. So, if there is a decrease in your antifreeze, there could be a leak in your car's coolant system.

One quick fix requires topping off with the same coolant in use in your car. But, this does not mean that you should leave the problem be. There may be other problems that can lead to your engine overheating. If your car's engine is having trouble operating, it might make it so your car's heater cannot blow hot air.

Blower Fan In Trouble

Broken motor fan

Another reason for a failing car heater is a broken blower fan. If your car's blower motor gets damaged, you might hear strange sounds coming from your blower. And, it might not blow any air, or only intermittently.

The blower fan pushes air through the car's system that has passed to the ducts and evaporator, or the heater core. Depending on where the blower fan pushes the air, it will process if the air is cold or hot. A malfunctioning blower fan can spell trouble for your entire climate control.

Malfunctioning Thermostat

modern cockpit with fokus on the needle on the water measuring instrument

And, last but not least, the most common reason for a failing heater is a broken thermostat. The thermostat controls your engine's temperature by isolating it from the radiator. A broken thermostat can also lead to the car's engine overheating, which can affect your climate control system. 

What Can Cause A Broken Car Heater?

There are more than a few problems that can cause your car heater to break. But, one of the biggest culprits that leads to a malfunctioning car heater is poor engine maintenance.

Engine Problems

Failing to schedule an oil change on time, overloading your engine's capability, and bad driving habits can all affect your heater. Ensuring that the air filters get cleaned regularly also helps maintain your vehicle's climate system. 

The engine is the heart and soul of your car. It is where your vehicle draws power to operate every single mechanical and electrical part. The engine makes your car run and keeps the transmission going, so you can move your vehicle. 

Leaking Radiator

Radiator problems are another probable reason that you have an issue with your car heater. A simple leak that can go unnoticed could spell a world of disaster for you. 

Sometimes, failing to secure your radiator cap leads to your coolant irregularly evaporating. So, always make sure that you seal the radiator cap on tightly and that it's not loose. 

Maintenance Checks

Also, it is also very important that you regularly check your oil level and coolant level at least every couple of weeks depending on how much you use your car. If you are using your vehicle for long daily drives, making frequent check-ups will help you keep on top of things.

Preventive maintenance is beneficial. You should regularly check on the moving parts of your vehicle, and inspect for any damage so you can use your car safely and remedy problems.

Scheduling car maintenance can help with immediately identifying a problem with your vehicle. So, you can expedite repairs made by a licensed mechanic to avoid further damage. 

So, if you are driving along on a cold day, your heater is not likely to suddenly fail on you. As the saying goes, take care of your car and it will take care of you. 

How Much Does It Cost To Get A Car Heater Fixed?

The cost of having your heater fixed will vary depending on what is causing the malfunction. But, you can expect to pay anywhere between $300 and $1000.

Now, this is only a conservative estimate. The price of repairs depend on whether there is significant damage to your radiator and engine already present. Or, if the car has already seen a lot of mileage the price will vary.

Car neglect and a lack of proper maintenance can happen when your vehicle has been sitting in a garage for decades. Consider your car's air conditioner, as it uses a compressor to blow cool air into your cabin. After long periods without use, the compressor can develop damage when you turn on the air conditioner because of system shock.

Don't forget about the cost of labor for specific repairs. The prices depend on your location and the type of mechanic that you will need to do the repairs. 

We highly advise against DIY repairs or YouTube tutorials, especially if you lack the experience and working car knowledge. Diagnosing problems can be very difficult, even for professionals, and this may end up breaking more parts instead of fixing them.

We recommend you call a trusted mechanic to look at your vehicle if you are experiencing some trouble with it. 

Are The Source Of My AC And Heater In The Car The Same?

No, your AC and car heater do not draw from the same source. The car's heater draws hot air from the radiator, where it uses heated engine coolant to warm the air being blown inside the vehicle.

The air conditioner uses a compressor that is connected to your car's engine to produce cold air through your climate system. To produce cold air, it uses refrigerant, which is the same chemical used to cool freezers and home refrigerators. 

That is why you can have a damaged air conditioner but you can still use your car's heater, and vice versa. There are some instances when both climate control systems are malfunctioning, especially if you are suffering from major engine problems. In that case, you might need to get an engine overhaul, or worse, a brand new one. 

Can A Blown Fuse Cause Heater Not To Work?

overburned fuse of a car which needed replacement

Another cause for your heater to stop working is electrical. Like modern houses, your car has its electrical system, including some vehicles that are fully running on electricity. Your vehicle uses electricity to run the lights, displays, electronic parking brakes, and the air conditioner and heater. 

And like a house, there is also a fuse box in your car. These fuses protect your electronics from sudden surges of electricity.

Now, a fuse is a link in an electrical circuit that contains just the right amount of electricity to run the connected electronics on it. Faulty electronic wiring can cause your fuse to blow up, or not receive commands being input into the buttons of the climate control. 

You can also have faulty buttons and controls, where it cannot send any signal to your system. So, you cannot activate or change the temperature of your climate control. 

That is why it is important to have someone do a thorough check of your vehicle, so they can determine the reasons your car is experiencing heater problems.

Your car might only have problems because of a broken fuse or a faulty HVAC control. But, if there is a misdiagnosis, you might end up purchasing a brand new radiator, or a brand new engine instead. A misdiagnosis can cost way more than what you would have spent if you took your vehicle in for a professional check-up.  

What Car Brands Have The Best Climate Control System?

Technology has so improved over the past decade, that innovations in vehicles occur every month. And the competition for climate control among different car brands has been very good, making it a treat for consumers. 

Bugatti hypercars have the most powerful car AC system in the world. While normal car brands like Nissan, Toyota, Ford, and Hyundai all have reputations for making decent climate systems at a cheap price tag. 


Heater in deck of a car malfunctioning, Car Heater Not Working - What Could Be Wrong? [Key Reasons Explored]

Troubles with your car heater can start becuse of many issues, as multiple car parts work together to produce heat for your vehicle. Your car's AC and heater do not have the same source, and one can function while the other not functioning.

Avoiding DIY repairs will help you save more money in the long run, as you should let the professionals handle diagnosis and repairs for you. 

Here are some related posts that we have previously written just for you. Check them out!

How To Defog Your Windshield Without Using The Heater

How To Manually Light RV Furnace And Water Heater

How To Flush A Heater Core In A Jeep Cherokee

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