Skip the auto shop - Our mechanics make house calls

Q: Heat control blows hot then cold air

asked by on

Heat control blowing warm then cold air. While on heat.

My car has 4300 miles.
My car has an automatic transmission.

A: This may be due to a bad heater core. As yo...

This may be due to a bad heater core. As you may know, the heater core is a small radiator like unit that circulates the hot coolant from the engine through the heater core which then uses this warm coolant to heat the inside of the car with the help of the blower motor that blows the warm air through the vents inside the car. I would recommend having an expert from YourMechanic come to your location to diagnose and repair your heater core.

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

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: Car independently accelerates - 2013 Porsche Panamera

Make sure to stay in touch with Porsche on this issue. It is possible the Idle Air Control valve, which "adjusts" engine idle speed, is faulty, or is receiving an incorrect signal to raise the engine RPM (say for air...

Q: Battery and alternator are good, yet there is a slow crank when trying to start the car. Battery saver mode is on.

Hello. Battery saver mode comes into play when the electrical system voltage is too low. This mode shuts off "non-essential" components like the AC compressor in order to "get you to a safe place" before the battery is dead. There...

Q: My oil light does not come on when the oil is low, and the heater only blows hot air for a short time.

When the oil pressure drops lower than 8 psi, then the oil light will come on. If the oil pressure drops and there is no light, then check the oil pressure sensor harness for power. If there is power, then...

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...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
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.