Low coolant is the first thing to check, with the engine cold. Other causes are a stuck thermostat, a clogged heater core, loose hoses, failed heating controls, coolant leaks and air in the cooling system. Most of these need a mechanic.
Sitting in a cold car in the winter and freezing isn’t the coziest feeling, but no worries, you’re not the only one.
Car heaters blowing cold air is a pretty common car problem, but still, it’s one of the most frustrating issues you can deal with.
There are a few basic issues that are leading to your car heater not working properly, so let’s dive deep into each one.
6 Reasons Why Your Car Heater Is Blowing Cold Air
1. Coolant in the engine is low
Your car’s heater gets its heat from the engine’s coolant, so it is normal for it to blow cool air for the first minute or two until the engine warms up.
Warm coolant flows from the engine through the heater core, and the blower pushes air across it to warm the cabin.
When your coolant is too low, not enough warm coolant reaches the heater core, so check the coolant level and top it off. Do it with the engine cold: never open the coolant cap on a hot engine. If the level keeps dropping, you have a leak.
Check the hoses and connections for leaks while you are there.
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2. Problem with the heater core
When the heater does not work, a problem with the heater core is one possibility.
The heater core can be clogged, or coolant may not be reaching it because of loose heater hoses or a stuck valve.
It’s important to figure out the exact issue within the heater core to prevent further, more serious damage.
Some of the most common signs of heater core problems are:
- Fog inside the car
- Weird smelling odor
- Car draining coolant quickly
- The engine overheats easily
3. The thermostat stopped working
The best sign that your thermostat isn’t working properly is if you notice that your temperature gauge still shows “C” after you start your car.
A thermostat stuck open or closed can cause cold air, because it controls the flow of coolant through the engine.
4. Heating controls stopped working
Sometimes the heating controls or the actuator behind the dash fail. Knocking or clicking from the dash, or airflow that comes and goes, can be a sign.
When these controls are broken, it’s impossible for your heating system to listen to selected commands.
5. There are coolant leaks
A coolant leak lowers the level in the system and the cold air comes back.
Check under the car and under the dash for dampness.
Cars work with multiple parts working together, so a coolant leak can leave the heater core without the hot coolant it needs.
Leaks often come from a hose, the water pump, or the radiator.
6. The cooling system has air in it
It can happen often that air gets stored in the cooling system which affects your heating system as well.
This can happen after the coolant has been topped up or serviced. A mechanic can bleed the air out of the system.
These 6 reasons are the most common ones. Checking the coolant level is the only quick fix most drivers can do themselves; the rest usually need a mechanic.
If the air is weak rather than cold, the cause can be a blown fuse, a failing blower motor or a clogged cabin air filter. If you still haven’t solved the problem, reach out for professional help to prevent further damage.
Car heating is important same as your household heating, so you can look at multiple ways to heat your home efficiently.
Content writer from Croatia. Dominic studies Information Science at the University of Sarajevo, which helps him research and organize his work.
![Why Is My Furnace Blowing Cold Air? [7 Reasons]](/wp-content/uploads/heater-is-blowing-cold-air.png.webp)
