Why Would a Car Heater Blow Cold Air?
It’s a common-enough problem. You fire up your vehicle, crank the heat, and wait for warm air to start blowing. After a few minutes, it’s still cold - and so are you. There are a few common causes of a car heater not working, and most of them are related to either low coolant levels or a faulty thermostat.
Follow this checklist to find out the root cause of your car’s heating problem and when to bring it into Garfield Auto Service Center for repairs.
Why Is My Heater Blowing Cold Air in My Car?
Your vehicle’s heat system is linked to its cooling system in that it uses the same coolant and many of the same heating and cooling control elements.
Here’s a look at the parts that turn on the AC and heat in cars and trucks:
HVAC panel: The HVAC control panel includes all user-controlled settings that let you adjust temperature, fan speed, and direct airflow into the cabin or to your vehicle’s defrosting mechanisms.
Blower motor: An electric motor that pushes hot (or cold) air through the system. The control panel sets its fan speed.
Blend doors: These are the small flaps in your dashboard that open and close doors based on the control panel settings. Closing the blend doors directs airflow away from that area of the vehicle, usually to our feet or through the dash vents.
If your vehicle is blowing air, these components are working fine. The issue is more likely to be caused by the parts that produce heat in your.
Read More: The Basic Car Maintenance Checklist for TC Drivers
How Cars Produce Heat
Cars generate heat by circulating engine coolant through the heater core, which is a small radiator located behind the dashboard. The heater core acts as a heat exchanger, transferring heat from the core to the coolant. Depending on your control panel settings, you can adjust how hot the heater core, and as a result, the coolant, gets, blowing warmer or cooler air into the cabin.
So, why would a car heater blow cold air?
What to Check if Your Car Heater Is Not Working
The most common causes of a faulty car heater are low coolant levels, thermostat issues, heater core clogs, and blower issues. We’ll explain each of these three common culprits.
Low coolant levels: The most frequent cause of a car heater blowing cold air. Coolant transfers heat from the engine to the heater core, and if levels are too low, it can’t transfer heat quickly enough to meet your temperature requirements.
Leaks in the radiator, hoses, or other components are usually the root cause of low coolant levels. The best way to stay ahead of this issue is with regular maintenance.
Thermostat Issues: Just like in your home, your thermostat adjusts how warm or cold your internal temperature will be.
If the thermostat is stuck open, it allows continuous coolant flow. This prevents the engine from warming the coolant enough to generate warm air.
If the thermostat is stuck closed, it can cause your engine to overheat, leading to significant damage.
Heater core blockages: When the heater core is clogged, it restricts the flow of warm coolant. This results in lower temperatures and a chilly cabin. The most common sign of a clogged heater core is a sweet antifreeze smell.
What to Check if Your Car Heater Isn’t Working
You can often narrow down the root cause of your car’s heating problems with a little sleuthing.
Check coolant levels: If your coolant is low, bring your vehicle in so we can rule out leaks.
Check air flow: With the heat on full, place your hand over all vents throughout the cabin. If one is weaker or isn’t flowing air, there may be a blockage in the blend doors.
Check engine temperature: Let your engine run for a while, then check the engine temperature gauge. If it isn’t warming up very much, the thermostat may be stuck open.
Unfortunately, there’s no DIY solution for most car heating problems, but trust that Garfield Auto knows how to fix your car's heater, no matter the make or model.
Turn Up the Heat with Garfield Auto Service Center
For over forty years, we’ve helped keep Northern Michigan families on the move with reliable, affordable repair services. Our friendly, knowledgeable technicians take the time to thoroughly inspect your vehicle, explain all your options, and recommend the best course of action for your car and your budget. Schedule your appointment with us or call (231) 929-3862 today!