Skip the auto shop - Our mechanics make house calls

Q: Heater

asked by on

The.heater only runs on cold an the person who had it last said that there some type of switch under the dash but I'm not sure where it is
My car has an automatic transmission.

A: The heater uses hot engine coolant to warm ...

The heater uses hot engine coolant to warm the vehicle cabin. If the heater is blowing cold, the first thing to check is the coolant level. Low coolant, or a problem somewhere in the cooling system, will affect heater operation. Other potential causes include a thermostat that is stuck open (not allowing the engine to reach operating temperature), air in the cooling system or a bad heater core. I recommend having a professional, such as one from YourMechanic, diagnose and repair this heating problem for you.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: About to purchase a 1985 Buick with 300k miles. Has a new paint job and a new radiator already. Heat from engine when opened hood

Hello. Especially with the indicated mileage, I would be concerned about excessive heat, and low fluids - both oil and coolant. Also, sounds like radiator hoses are way too old. The new radiator is also a clue that the car...

Q: Anti-theft system issues after leaving key in overnight. Car won't start.

Hello. From what you describe it would appear that your security system may be activated and needs to be reset. This likely happened as a result of leaving the keys in the vehicle overnight. The procedure for resetting the security...

Q: Car moving from side-to-side when driving

Hello, I'm not quite sure what you mean that it moves side to side. Being that it is affecting the drivability of the vehicle, it should be inspected and repaired sooner that later. You will probably need the aid of...

Related articles

P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.