How to Replace the Heater Core in a Honda Accordby Contributor; Updated November 07, 2017
Items you will need
Replacement heater core
How to Replace the Heater Core in a Honda Accord. Replacing the heater core in your Honda Accord shouldn't be attempted without complete knowledge of the car's interior. You must remove the dashboard to reach the heater core, which is connected to the center console, as well. This complex task may be best left to an expert.
Unclamp the Honda Accord's negative battery cable and wait 3 minutes for the air bag system to run out of energy.
Discharge the air conditioning system by disconnecting the suction and the receiver lines from the evaporator core. Drain the coolant from the system by placing a pan underneath the drain plug at the bottom of the radiator and opening the plug to empty the coolant.
Raise the hood and open the cable clamp. Disconnect the heater control cable and turn the valve to the fully opened position. Remove the heater hoses from the core assembly and take off the mounting nut from the heater unit.
Remove the center console from the interior. This includes the gear shift knob (if you have a manual transmission), heat switch connectors (if you have heated seats), front power accessory connector, console mat and rear accessory electrical connector.
Detach the lower dashboard covers, center pocket assembly and glovebox. Also, take off the driver's side under cover panel on newer models of the Honda Accord.
Separate the steering column from the dashboard. Remove the air bag assembly first and make sure the column is in the full up position during removal. Hold the slider shaft onto the column with a piece of wire during removal.
Have another person help you remove the dashboard assembly. You must disconnect the center lower covers on both sides, the SRS control unit and all connectors, hoses and harness that will interfere with the dashboard removal.
Disconnect all connectors to the air mix control motor, evaporator temperature sensor, power transistor and recirculation control motor. Remove the wire harness, heater ducts and blower-heater unit. Loosen the heater core cover and remove the heater core.
Install the new heater core in place. Reconnect everything in reverse order of removal. Refill the coolant and test the system at normal operating temperatures, checking for leaks.
Take note of the anti-theft code from the radio before disconnecting the battery, which will be erased upon disconnection. Because you disconnected the battery cable, be sure to test everything electrical in the car. This includes the clock, power locks and power windows. You must also re-enter the radio and the navigation system's anti-theft codes.
For best results, consult with an expert to make sure you know how to remove the center console and dashboard before starting this project.