2007 Tahoe Heater Issue - Intermitten Cool AIr

[Plimbob]

I am getting an occasional instance were the heater starts blowing cool air. I checked for leaks at the heater coil and didn't find any. Coolant level is normal and running temp is normal.

Anyone had this issue?

 

[mals]

I am getting an occasional instance were the heater starts blowing cool air. I checked for leaks at the heater coil and didn't find any. Coolant level is normal and running temp is normal.

Anyone had this issue?

I had the opposite this past summer where my a/c would occasionally blow hot air. Turned out to be the air blend door actuator.

 

[Plimbob]

I had the opposite this past summer where my a/c would occasionally blow hot air. Turned out to be the air blend door actuator.

Thomas, thanks for the information. I'll research that.

Tim

 

[sumo]

I had a similar problem. I did my coolant and replaced my thermostat. Not as hot as it could be and also cool air blowing from pass side. I did a Hvac system reset and I bled my cooling system to remove and trapped air.
What I did was turn the temp to hot, remove the coolant cap and jacked up the front end and let it run until the fans cycled a few times. Doing this allowed trapped air in the system to work it way to the top.
So far everything is good

 

[Plimbob]

I am getting cool air through all the dash vents. I thought there were multiple blend door actuators, how do you test to determine which one went bad?