Q: no heat coming out of heater

asked by on

radiator full of water / hoses going in and out of heater core are hot / fan works / How do I diagnose heater actuator what fuse do i check also
2004 chevy express 3500 6.0 motor

My car has 250000 miles.
My car has an automatic transmission.

Hello, thank you for writing in. Check the radiator hoses as well, and make sure both are warm if not hot. If the engine itself is running too cold, by the time the coolant gets to the heater core it is even colder. To check the blend door actuators, you will need to remove the glove box and most of the dash to access them and the main unit. You will highly benefit with a repair manual that walks you through the procedure if attempting at home. With that being said, you should rule out your switch and the engine temperature first. The fuse box in the engine compartment under the hood will have some HVAC fuses, and should be #21 or #22. For more help resolving the issue, contact our service department to schedule an appointment.

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. no heat coming out of 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: Causes for heater to blow cold air

Hi...if you are referring to the passenger compartment heater, there are two possible causes of insufficient or no heat. The passenger compartment heater, also known as the "heater core", is essentially a mini radiator and the fluid running through this...

Q: Gas pedal shakes when accelerating fast and misfire code came on?

Hello, thank you for writing in. The most common cause of engine or pedal shake (because you can feel the engine shake in the pedals) is a misfire. With that being said, its not uncommon to feel issues with brakes,...

Q: Engine overheating replacing thermostat

Hello. Let me start off by saying that it is just as bad, if not worse, to run an engine with no thermostat as it is to run it with a bad one. It will also cause engine damage. It...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...
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.