Heater Core Plugged
WARNING: The heater core inlet hose will become too hot to handle if the system is working correctly.
Check to see that the engine coolant is at the proper level.
Start the engine and turn on the heater.
When the engine coolant reaches operating temperature, feel the heater core outlet hose to see if it is hot.
If it is not hot:
the heater core may have an air pocket
the heater core may be plugged.
Thursday, December 6th, 2018 AT 5:21 PM