Heater not working

2004 CHEVROLET AVALANCHE
120,000 MILES • V8 • 4WD • AUTOMATIC
Avatar
DENISE WHITE
  • MEMBER
  • 2 POSTS
I had issues in the past where I could not get the air to come down to the vents or it would be hot air. Still having issues but now I only have cold air blowing no heat at all.
Dec 7, 2017 at 9:28 AM
Advertisement
Avatar
JACOBANDNICKOLAS
  • ✓ASE Certified Mechanic
  • 110,194 POSTS
  • ASE Certified Mechanic
Start the engine and turn the heater on high. Allow the engine to reach operating temperature. At this point, feel both heater core hoses. Both should be hot. If they are, you have a bad blend air door actuator.

https://www.2carpros.com/articles/replace-blend-door-motor

If only one is hot and the other cold, suspect a plugged heater core. Here is a list of the most common problems:


https://www.youtube.com/watch?v=SNRb6pSwYuU

Let me know what you find.
Dec 7, 2017 at 6:48 PM
Avatar
DENISE WHITE
  • MEMBER
  • 2 POSTS
I checked the hoses one is hot the other one was barely warm.
Dec 10, 2017 at 3:21 PM
Avatar
STRAILER
  • ✓ASE Certified Mechanic
  • 54,832 POSTS
  • ASE Certified Mechanic
Yep it sounds like you have a plugged heater core. Can you remove the heater hoses and use a garden hose to blow through it please?

Here is a guide that can help you as well.

https://www.2carpros.com/articles/car-heater-not-working

Please let us know what happens.

Cheers, Ken
Dec 16, 2017 at 1:14 PM
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.
Ask a Free Question
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.