Heater Core - Plugged

Climate Control System

Component Tests

Heater Core - Plugged

1. Check to see that the engine coolant is at the correct level.

2. Start the engine and turn on the heater.

3. When the engine coolant reaches operating temperature, using a suitable temperature measuring device, check the core inlet and outlet hoses to see if they are hot.

4. If the outlet only is not hot:
- the heater core may have an air pocket.

- the heater core may be plugged.

5. If the inlet only is not hot:
- the thermostat may not be working correctly.