What should I do if I get heat from my Blend door?

What should I do if I get heat from my Blend door?

Remove the blend door actuator and operate the blend door by hand to see if you get heat. If you do, the problem is with either the blend door actuator or the HVAC control module. You have all the symptoms of a plugged heater core. Inlet and outlet temps of the heater hoses should be very close.

Why is the outlet Hot when flushing the heater core?

The OP states he has good flow when trying to flush the core yet when the truck is operating the inlet hose is hot and the outlet is cool. That certainly points to a restricted heater core. If the heater core was plugged but the coolant was able to circulate around it without exchanging any heat then the outlet hose would still be hot.

Why is the coolant not flowing through the heater core?

The thermostat was never mentioned. Also, the coolant may not be flowing through the heater core for reasons other than the obvious. The thermostat may be the culprit if you get half the normal amount of heat when the engine is fully hot.

Is the inlet hose to the heater core hot?

I even drianed the entire system and evacutated all the air out of the system and put a vaccum under and filled the system back up still nothing. The inlet hose to the heater core is very hot it comes out of the front of the engine but the out let hose is warm no where close to hot.

Remove the blend door actuator and operate the blend door by hand to see if you get heat. If you do, the problem is with either the blend door actuator or the HVAC control module. You have all the symptoms of a plugged heater core. Inlet and outlet temps of the heater hoses should be very close.

The OP states he has good flow when trying to flush the core yet when the truck is operating the inlet hose is hot and the outlet is cool. That certainly points to a restricted heater core. If the heater core was plugged but the coolant was able to circulate around it without exchanging any heat then the outlet hose would still be hot.

The thermostat was never mentioned. Also, the coolant may not be flowing through the heater core for reasons other than the obvious. The thermostat may be the culprit if you get half the normal amount of heat when the engine is fully hot.

I even drianed the entire system and evacutated all the air out of the system and put a vaccum under and filled the system back up still nothing. The inlet hose to the heater core is very hot it comes out of the front of the engine but the out let hose is warm no where close to hot.

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