Description
Heater Servo Motor for CITROËN C4 and PEUGEOT 307 II
This BEHR heater servo motor is a direct-fit electro component for Citroën C4 and Peugeot 307 II HVAC systems. Commonly referenced under codes such as H1959 U b 21, EAD512 or 6447RZ/6447RF, this actuator controls airflow direction and temperature blending inside the heater box. Ideal for professional workshops and experienced DIY mechanics, the unit restores precise flap positioning and eliminates common HVAC faults such as incorrect temperature distribution, stuck vents or noisy operation.
Technical Information
- Manufacturer: BEHR
- Model: Citroën C4; Peugeot 307 II
- Product Codes: H1959 U b 21; EAD512
- Additional Numbers: 6447RZ; 6447RF
Function and Application
The servo motor (blend door actuator) operates the HVAC flaps inside the heater box to regulate cabin temperature and airflow direction. It receives position commands from the climate control unit and moves internal plastic gears or a potentiometer assembly to position the mix and mode doors. Proper operation is essential for accurate cabin temperature control, defrosting and passenger comfort.
Compatibility / Fitment
Fits Citroën C4 and Peugeot 307 II HVAC systems in the configurations where the original BEHR-type actuator is used. The part is typically sought by part number, so verify the listed product codes against the existing unit to confirm fitment.
Installation Recommendations
- Always Disconnect The Battery Before Starting Work To Avoid Short Circuits And Protect The Vehicle Electronics.
- Access The Unit Through The Glovebox Or Lower Dashboard Panel On The Passenger Side; The Actuator Is Mounted On The Heater Box Inside The Dashboard.
- Unplug The Electrical Connector And Remove Retaining Screws Or Clips. Note The Orientation Of The Linkages And Connectors For Correct Reinstallation.
- Inspect The HVAC Flaps For Free Movement And Any Debris That Could Obstruct Operation Before Installing The New Motor.
- After Installing The New Actuator, Reconnect The Battery And Cycle The HVAC System To Verify Full Range Of Motion And Correct Response Before Reassembling Panels.
- If Extensive Dashboard Disassembly Is Required Or If HVAC Calibration Is Needed, Consider Professional Assistance.
Most Common Failure Causes
- Wear Of Plastic Gears Or Internal Potentiometer Resulting In Loss Of Accurate Position Feedback.
- Moisture Ingress Or Condensation Causing Corrosion Or Electrical Failure.
- Mechanical Obstruction In The Heater Box (Debris, Broken Flap) Preventing Free Movement.
- Connector Corrosion Or Wiring Faults Leading To Intermittent Operation.
- Ageing And Repeated Thermal Cycles Causing Gradual Degradation Of Internal Components.
Why Choose This Part
Offers a direct-fit replacement that restores proper HVAC functionality for Citroën C4 and Peugeot 307 II vehicles. Frequently replaced part in workshop repairs, it provides reliable flap control and reduces symptoms such as incorrect cabin temperature, noisy actuators or stuck vents. Ideal for mechanics and experienced DIYers who search by part number for a fast, precise repair.
