Heater not working

2004 CHEVROLET SUBURBAN
195,000 MILES • 5.3L • V8 • 2WD • AUTOMATIC
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WILLIEJNS
  • MEMBER
  • 1 POST
I've changed the thermostat and the coolant reservoir. I have good pressure just no heat.
Dec 12, 2020 at 12:04 PM
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JACOBANDNICKOLAS
  • AUTOMOTIVE REPAIR CONTRIBUTOR
  • 110,190 POSTS
Hi,

First, take a look through this link and let me know if it helps:

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

Here is what I suggest: Start the engine and allow it to reach operating temp while the heater is on high. Once it reaches temp, see if both heater core hoses are hot. If they are, chances are the problem is related to the blend air door. If only one gets hot, then chances are the heater core is plugged.

So, if you find both heater hoses are hot, here are directions in general for replacing the blend air door:

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

Since the vehicle has dual climate control, if both sides are not working and it happened at the same time, there is a good chance the heater core is plugged.

Try what I suggested and let me know what you find.

Take care,
Joe
Dec 12, 2020 at 8:48 PM
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