Bentley GT Heater Box Air Conditioner Heater 3D1820003M

For the Bentley Continental GT, GTC, and Flying Spur (2004–2013), the part number 3D1820003M identifies the Main HVAC Heater Box (Climate Control Housing).

This is the primary unit located behind the dashboard that houses the heater core, A/C evaporator, and the various blend door actuators that direct airflow to the vents.

1. Technical Specifications

• Function: Integrates the heating and cooling elements into a single unit. It manages multi-zone temperature control for the cabin.

• Core Components: Usually includes the Evaporator Core, Heater Matrix (Core), and the complex series of Flap Actuators.

• Supersession: This part number has been superseded by 3W1820003C. When ordering new from Bentley, the 3W version is the updated standard.

• Compatibility: * Continental GT/GTC: 2004–2012 (Generation 1).

  • Flying Spur: 2005–2013.

  • Drive Type: Specifically for Left Hand Drive (LHD) models. (Right Hand Drive models typically use the 3D2 prefix).

2. Common Reasons for Replacement

Replacing the entire heater box is a major undertaking, usually reserved for:

• Evaporator Leaks: If your A/C is losing gas and the leak is traced to the dashboard, the evaporator inside this box is the culprit.

• Heater Core Failure: If you smell coolant inside the cabin or have wet carpets, the heater matrix may have cracked.

• Broken Blend Doors: If the internal plastic gears or doors snap, the car may only blow hot air on one side and cold on the other.

3. The “Dashboard Out” Labor

Critical Note: Replacing this unit is one of the most labor-intensive jobs on a Continental GT. It requires the complete removal of the dashboard, steering column, and center console. This is often a 20+ hour job in a professional workshop. If you are buying a used unit, it is highly recommended to pressure-test the internal cores before installation to avoid doing the labor twice.