The sensor performs two important monitoring functions within the heater. It monitors heater startup and the temperature of the heat exchanger, helping the heater control system monitor combustion and protect against excessive temperature.

Part 416820 corresponds to Eberspächer part number 252069010200, also formatted as 25.2069.01.0200.

The sensor is compatible with specified Airtronic D2, D4, D4S and related heater configurations. The component is suitable for both 12V and 24V versions where part 252069010200 is specified.

Because multiple Airtronic generations and configurations exist, always confirm the complete heater identification number before ordering.

Key Features

• Genuine Eberspächer/ESPAR replacement sensor
• Combination flame and overheat sensor
• Monitors heater startup
• Monitors heat-exchanger temperature
• Compatible with specified Airtronic D2 heaters
• Compatible with specified Airtronic D4 heaters
• Compatible with specified D4S configurations
• Suitable for specified 12V and 24V heaters
• Corresponds to Eberspächer part number 252069010200
• Suitable for heater repair and maintenance

Specifications

• BTRAC Part Number: 416820
• Eberspächer Part Number: 252069010200
• Formatted Eberspächer Number: 25.2069.01.0200
• Product Type: Flame and overheat combination sensor
• Primary Function: Heater startup and heat-exchanger temperature monitoring
• Heater Family: Airtronic
• Compatible Models: D2, D4, D4S and specified related applications
• Voltage Compatibility: Specified 12V and 24V heaters
• Brand: Eberspächer/ESPAR
• Condition: New replacement part
• Unit of Measure: Each

Compatible Eberspächer/ESPAR Heaters

Part 416820 is intended for compatible:

• Airtronic D2 12V
• Airtronic D2 24V
• Airtronic D4 12V
• Airtronic D4 24V
• Airtronic D4S 12V
• Airtronic D4S 24V
• Airtronic D4 Plus
• Selected B4 Airtronic applications
• Other heaters requiring sensor 252069010200

Always confirm compatibility using the heater identification label and complete heater number before ordering.

Common Service Applications

The flame and overheat sensor may require replacement when:

• Electrical diagnosis identifies a sensor failure
• The sensor is physically damaged
• The wiring or connectors are damaged
• The heater experiences a related temperature-monitoring fault
• The heater is undergoing internal repair
• The combustion system is being serviced
• A technician has diagnosed the combination sensor as the failed component

A heater shutdown or fault code does not automatically indicate a failed sensor. The heater should be properly diagnosed before the sensor is replaced.

Important Installation Notes

• Confirm the complete heater model and identification number.
• Verify that the heater requires sensor 252069010200.
• Disconnect electrical power before servicing the heater.
• Allow the heater to cool completely before disassembly.
• Inspect the sensor wiring and electrical connectors.
• Inspect related internal heater components during service.
• Check disturbed seals and gaskets before reassembly.
• Install the sensor in the correct position.
• Route the wiring according to the original heater configuration.
• Test heater operation after completing the repair.

Related Products and Cross-Sell Suggestions

• 417745 – Eberspächer/ESPAR Airtronic D2 Flame Tube
• 417745AM – Eberspächer/ESPAR Airtronic D2 Aftermarket Flame Tube and Gasket
• 334181 – Eberspächer/ESPAR Airtronic D2 Burner Gasket
• 334183 – Eberspächer/ESPAR Airtronic D2 Blower Gasket
• 420453 – Eberspächer/ESPAR Airtronic D2/D4 12V Glow Pin
• 416816 – Eberspächer/ESPAR Airtronic D2 12V Combustion-Air Blower
• 416824 – Eberspächer/ESPAR Airtronic D2/D4 12V Fuel-Metering Pump
• 925040 – Eberspächer/ESPAR Airtronic D2/D4 Combustion-Air Intake Hose
• DH-E1000-MAINT – Eberspächer/ESPAR Airtronic D2 12V Maintenance Kit