My Car Heater Isn’t Working, What Should I Do?

During the hot summers in Utah, the last thing you are thinking about is whether or not the heat in your car works. As the seasons start to change and the weather gets colder, most drivers expect no issues when they turn the heater on in their car. Sometimes, after months of no use, you may turn the heater on to find cold air, or no air at all, coming through the vents. If you find yourself in this situation, you are probably wondering what went wrong?

How does the heater work in a car?

The hot coolant is sent to the heater core once the engine is up to operating temperature. A fan then blows over the heater core, pushing the hot air into the car. 

Why is my car heater not working?

If your heater isn’t working, there are several potential reasons why. Repairing this issue can vary in difficulty and cost. A certified technician will be able to tell you the exact cause of your heating issue.

Low coolant

The coolant that enters the heater core is also used to keep your engine at the proper operating temperature and prevent overheating. If you are not feeling the heat coming through the vents once your car has warmed up, the first thing to check is your coolant level. Low coolant will prevent the heater core from filling, reducing its effective heat distribution.

If you want to check your coolant level yourself, BE CAREFUL. When the engine has been running, the coolant is pressurized and extremely hot. Read your vehicle’s owner’s manual and check the level without opening the reservoir if possible.

Low coolant can indicate a coolant leak. With the hood up, examine visible hoses for signs of seeping or leaks. Be sure to check the ground under where you parked for drips or coolant puddles.

Heater Core Issues

Heat issues can stem from a problem with the heater core. A miniature version of the radiator found in the dash, the heater core is a component in the engine cooling system and is filled with hot coolant. The heat emitted from the heater core is blown into the cabin, keeping you warm.

Your car is far less efficient when the engine is cold and can emit a lot more pollution. The thermostat keeps coolant circulating through the engine when it’s cold to warm it up quickly. This is why you don’t feel the heat coming through the vents when you first start your car. 

Once the engine is warm, you normally feel the heat coming through the vents as the thermostat opens and allows hot coolant into the heater core. However, if the coolant is unable to flow freely through the heater core, your heater will not work as it should.

Infrequent coolant flushes can lead to corrosion and rust. These particles can clog the heater core and prevent the free flow of coolant. Regular coolant flushes can prevent this condition from occurring.

Another cause of heater core failure is electrolysis. Electrolysis occurs when there is a chemical imbalance in the coolant system, creating an acidic environment. Under these conditions, electrical energy is generated within the system much like a car battery. 

Electrolysis causes corrosion, which may lead to your heater core leaking and clogging. This condition can also damage other parts of your vehicle’s cooling system. Electrolysis can be prevented with regular coolant flushes, and typically happens on older vehicles.

If you notice a sweet smell or fogged windows when the heater is on, you may have an issue with your heater core.

Failing Thermostat

The thermostat regulates the flow of coolant to the radiator, allowing your engine to heat up/cool down as needed during operation. Thermostats can fail in two ways. If it ends up stuck in the open position, coolant is allowed to flow through the radiator regardless of engine temperature. If this condition occurs, your engine will have trouble getting up to and maintaining operating temperature. You will feel this in the heating system as well, as the coolant in the heater core will not be as warm as it is when the thermostat is functioning properly.

Broken Heater Controls

The buttons and knobs that control the heat and AC in your car can become gummed up, wear out, and stop working as they should. If you have enough coolant and your heater core appears to be issue-free, your problem may be as simple as a stuck button.

Heater problems? Matson Point S Can help!

 Our team of expert technicians will diagnose and repair your heater issue the first time. Give us a call or schedule an appointment at our Riverton repair shop today!

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