Q: Broken heater

asked by on

When running my heat it comes out cool/Luke warm. My coolant levels are where they should be and I've even tried to release air pockets within the system nothing is working. My car gets to operating temperature just fine and both the in and out hose on the heater core get hot. I've considered a flush but since both hoses are warm I assumed there wasn't any blockage. Any advice? SOS it's getting cold outside

My car has 140000 miles.
My car has an automatic transmission.

If everything in the cooling system has been eliminated as a cause - coolant level, flow, thermostat operating properly, etc., the issue may lie with the heater controls inside the vehicle. Within the "heater box" under the dash is located the heater core and air conditioning evaporator. The blend door is responsible for diverting the air flow between the evaporator for cold air and the heater core for hot air. If the blend door is not moving properly to divert air through the heater core to get hot, then you can still be getting a mix of cool air albeit cooled air if the A/C is on, or simply outside air. Possible causes for the blend door not moving properly can range from the hinge mechanism itself binding or broken, or the cable and/or electrical signal to actuate the door being at fault. Have a certified technician inspect the heating system to locate the cause.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Broken heater

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: start and go

Your truck is equipped with an immobilizer that may be having a problem intermittently reading the key. The immobilizer is a security feature that has to recognize the chip built into you key in order for the vehicle to start....

Q: While driving defroster set to hot blows hot air as it should, while idling it is blowing cold air.

First, the coolant level should be checked to make sure the radiator is full. While the overflow tank may be full, the radiator cap must be taken off to check the level inside the radiator. If you find the level...

Q: Engine cooling fan works fully when it's cold

Hello. The cooling fan is activated when the temperature of the car reaches slightly above normal operating temperature. If the engine stays cool long enough, the cooling fans will not come on. If the engine gets warm but doesn’t overheat...

Related articles

Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.