Heater problem

2004 CHEVROLET AVALANCHE
175,000 MILES • 5.3L • V8 • 4WD • AUTOMATIC
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CAVALANCHE
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  • 1 POST
Heater gradually changes to cold air after about 10 - 15 minutes. Can’t get heat again until motor shuts off and completely cools down. After cool down, restart and heat starts working and gradually switches to cold.
Feb 13, 2020 at 5:41 AM
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ASEMASTER6371
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  • 52,796 POSTS
Good morning,

Do you mean the control head stops working?

When you have heat, is the air hot?

Have you checked the coolant level?

You could have a partially blocked heater core from debris in the system. Flushing the system would be a good start and replacing the thermostat.

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

Beyond that, if it is a control issue, the control head itself may be the issue.

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

Roy
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Feb 13, 2020 at 6:50 AM