As summer gradually turns into winter, it’s finally time to give your car’s air conditioner a rest. At the same time, you need your vehicle’s heater to come out of hibernation. Is yours ready for another bitter Fort Collins winter?
It’s possible your heater broke down in the summer unbeknownst to you until it came time to crank it on for the first time this fall. Learn what problems could cause your heater to work poorly and how to fix them.
How Does a Car Heater Work?
When you switch the temperature knob from the blue to the red, a number of things change unseen behind the dashboard.
First, a device called the temperature door directs air from the blower motor to pass over the heater core instead of the air conditioner evaporator coil. The temperature door is able to blend the amount of air flowing over these two heat exchange devices to let you customize the air temperature. In cars with dual zone climate controls, individual temperature doors control the driver and passenger side airflow separately.
Second, engine coolant begins to flow through the heater core, a process facilitated by the heater control valve. When operating normally, the hoses leading into and out of the valve should be about the same temperature.
What Can Go Wrong With a Car Heater?
Temperature Output Doesn’t Match the Control Setting
- Cause: Modern vehicles control the temperature door with an electric motor actuated by a computer module. If the motor is calibrated incorrectly or malfunctions for some reason, the driver may hear a clicking sound when attempting to adjust the temperature. The air output may not match the temperature reading on control setting.
- Fix: Bring your car to Scott’s Fort Collins Auto & Repair to have the temperature door repaired or replaced.
Not Enough Heat
- Cause: If the heater control valve gets stuck closed, the hose leading into it will feel hot while the hose leading out feels cool. This prevents the heater from producing ample heat.
- Fix: Bring your car to Scott’s to have the heater control valve repaired or replaced.
Lack of Airflow
- Cause: Air must flow over the heater core to warm up the vehicle’s cabin. If airflow is blocked, the heater may not blow properly.
- Fix: If airflow is blocked at the fresh air inlet, don a pair of work gloves and lift the hood. Clean out leaves, twigs and other debris you find clogging the inlet, which is usually located at the base of the passenger side windshield. If airflow is blocked by a dirty cabin air filter, you must have it replaced. Finally, if a faulty blower motor is to blame, bring your car to Scott’s for a repair.
Heater Blows Lukewarm Air
- Cause: Vehicle heaters draw heat from the engine. If the engine takes longer to warm up than normal, the heater isn’t able to produce enough hot air. One common cause is a thermostat stuck in the “open” position, which means a constant flow of winter-cold coolant inundates the engine, preventing it from heating up properly.
- Fix: Our mechanics can quickly and easily adjust your thermostat so your engine warms up quickly.
Erratic Heat Operation
- Cause: Your coolant could be low. Since the priority of the cooling system is to circulate coolant through the engine block and radiator, the heater core is the first thing to run dry. With no warm coolant available to flow through it, your heater performs erratically.
- Fix: Top off your coolant with a 50/50 mixture of water and antifreeze to see if this fixes the heater problem.
For help getting your car’s heater up and running again, bundle up and head on over to Scott’s Fort Collins Auto & Repair. If you would like, you can schedule an appointment online or call ahead at (970) 682-4202.