Why Is Your Car Heater Not Working Properly?

Why Is Your Car Heater Not Working Properly?

There are a few reasons why your car heater may not be working. Learn more about fixing these problems by checking out this guide.

Take the heat! The average American spends 18 days driving in their car every year. If you spend a lot of time on the road, you need to find tools to keep yourself comfortable. 

Your car heater helps you stay healthy and warm while you are driving during cold weather. Yet if you use your heater a lot, you should expect it to break down. Thankfully, you can take control of the situation once you study heater problems. 

What are some of the most common heater issues? What are some common car repairs you can make by yourself? When should you take your car to the professionals? 

Answer these questions, and you can stay toasty in your car throughout the year. Here is your quick guide.

Low Antifreeze

Antifreeze allows hot fluid to travel to the core of your heater. Fans can then distribute hot air throughout your car. When you run out of antifreeze, the fan will run, but you will only feel cold air. 

A light will usually switch on to indicate you have run low on antifreeze. You can go to an auto maintenance store or a garage to buy more.

Follow the instructions on the bottle and the manual for your vehicle, so you know how to refill the antifreeze container. You can also read a guide on checking and filling your coolant so you know what the experts think.

Even if the light has not switched on, you should open your hood and see if you have antifreeze. You should restock it, then you should go to a garage. Your engine parts may not be sending signals to your dashboard, preventing other lights from switching on. 


Grime and particles can clog your coolant system. If you notice warm but weak air coming out of your heater, or if you smell an odor coming from it, you may have grime in the system.

You can perform a coolant flush by cleaning your radiator with warm and soapy water. Drain the radiator using its drainage valve, and once it’s fully drained, pour in clean water. Start your engine and let the engine run for 15 minutes, then open the drainage valve again to remove the water.

Your coolant can start to develop clumps or particles after being in your car for a few months. You should swap out your coolant every six months if you haven’t used it.

Broken Thermostat

Your thermostat may be stuck open or closed, preventing air from circulating properly. To see how your thermostat is doing, you should remove the cap to your radiator and idle your engine.

If you notice the coolant flowing, your thermostat is stuck open. If it does not flow after 15 minutes, your thermostat is closed.

It is okay to run an engine with an open thermostat for a little while, but you eventually need to fix it. Fix a closed thermostat as soon as possible.

You can fix the thermostat by disconnecting the radiator hoses from your car engine. You can then swap out the valves in the thermostat hoses with new ones. 

If you’re not comfortable with fixing a car, you should go to an auto repair professional near you. You can drive the car to the garage, but keep the engine temperature low and avoid using your car heater. You should wear additional layers, so you stay warm.

Broken Controls

The system itself may be working, but your controls may not be triggering it. The buttons and knobs may not be connected to your system, causing nothing to happen when you use them. 

Try cleaning the buttons and knobs. You can use rubbing alcohol or a household spray to remove dust from your controls. Do not apply too much pressure, as you risk damaging your controls. 

If cleaning doesn’t work, you may want to go to a garage. The employees there can unscrew the buttons and knobs and perform a deep clean. They can also replace your controls and fix the wiring.

Broken Blend Door

The blend door controls how much heat passes from your heater core into the passenger compartment. The door can get stuck in place, preventing air from moving through, even if your controls are working. 

You may be able to see if your door is not working. Remove the vent over your heater and look into your system with a flashlight. If the door appears to be open, you probably have an issue with it. 

Take your car into a garage and talk to an automotive air conditioning specialist. Be gentle with using your heater, as the door can become stuck again.

Electrical Problems 

Several electrical problems can cause heater issues. Your fuses or fan motor may stop receiving electrical signals. A loose wire may cause your whole heater system to go offline, preventing you from feeling any warm air at all.

It’s hard to fix electrical issues by yourself. You may need to change out one fuse, but you may also need to replace several wires. If you don’t think you are experiencing other heater problems, you should take your car in and have the electrical system inspected. 

Fixing a Car Heater

Driving with a broken car heater can be uncomfortable and dangerous. If you notice something wrong with the heater, you should check the antifreeze levels and perform a coolant flush. If everything seems fine, you may have a problem with your thermostat. 

Your controls, blend door, and electrical system may also be broken. Inspect your engine to determine what the problem may be. Then take your car to professionals in automotive heating. 

Don’t drive far to find great car repair experts. A Plus Transmission and Auto Repair serves the Brighton area. Contact us today.