Description
Heating servo motor Magneti Marelli for CITROËN and PEUGEOT vehicles. For manual climate control.
Description
High-quality heater servo motor designed to restore correct flap movement and temperature regulation in vehicles with mechanical (manual) climate control. This unit is a direct-fit replacement commonly used on Citroën and Peugeot models, helping to eliminate stuck flaps, inconsistent cabin temperature and unusual noises from the heater box.
Key Benefits
- OEM-grade Magneti Marelli design for reliable fit and function.
- Direct replacement for affected Citroën/Peugeot models with manual HVAC systems.
- Restores precise airflow and temperature mix, improving comfort and defogging performance.
- Suitable for professional workshops and DIY mechanics — compact and straightforward to install.
Technical Information
- Manufacturer: Magneti Marelli
- Model: Citroën, Peugeot (Examples: Peugeot 307 II). Suitable for vehicles with mechanical climate control.
- Product Codes: A21900100, 6447KF
- Additional Numbers: NFP
Function
The servo motor drives the heater/air-mix flap(s) inside the HVAC housing, controlling airflow distribution and temperature blending. When operating correctly it ensures precise mixing between hot and cold air streams and reliable flap positioning for heating, ventilation and defrost functions.
Common Failure Reasons
Failures typically occur due to wear of internal plastic gears, fatigue from repeated actuation, ingress of moisture or debris into the heater box, or electrical faults such as worn motor brushes or connector corrosion. Symptoms include clicking or grinding noises, inability to change temperature, stuck flaps, and uneven cabin heating.
Replacement Guide
- Locate the servo on the heater box (usually under the dashboard, behind glovebox or lower dash panel).
- Remove the required trim panels or glovebox to access the unit. Keep screws and clips organized.
- Disconnect the electrical connector and note the actuator orientation and linkage positions.
- Unscrew the fastening screws, remove the old servo and transfer any required linkages or seals to the new unit if applicable.
- Install the replacement, secure screws, reconnect the connector and reassemble panels.
- Test all HVAC functions (temperature adjustment, air distribution, defrost) to confirm correct installation.
Installation Recommendations
- Always disconnect the battery before starting work on HVAC electronics to avoid short circuits.
- Work on a warm, dry day or in a dry workshop if possible to reduce moisture-related complications.
- If the old unit failed due to gear breakage, inspect surrounding linkage and flap for damage and replace as needed.
- Use correct fasteners and ensure the actuator is mounted in the same orientation to preserve calibration.
- After installation, cycle the HVAC controls through all positions to verify smooth operation and to seat gears.
Why Buy This Part
This Magneti Marelli heater servo motor offers a cost-effective way to restore reliable heating and airflow control in affected Citroën and Peugeot vehicles. Ideal for professional mechanics and competent DIYers who need a dependable, direct-fit replacement to eliminate noise, poor temperature control and malfunctioning flaps.
Notes
Part identification by product code (A21900100 / 6447KF) is commonly used when searching for compatible replacements. Always compare the physical connector and mounting pattern with the original unit before fitting.
