Stationary Heater Unit, Basic Function - GF83.70-P-2013A

MODEL ALL (CAR) with CODE 228 (Auxiliary heater) 

General 

The heater unit is the central component of the stationary heater. It comprises all components necessary for generating heat.

Function requirements 

• Circuit 30t ON
• Stationary heater switched on
• Fuel level above fuel reserve
• No overvoltage or undervoltage
• Interior and outside temperature have been determined.

Design 

The stationary heater unit is located in front of the right front wheel arch and mainly consists of the following components.

Function 

The stationary heater control unit starts the heating mode by actuating the combustion air blower in the heater. It also actuates the glow plug/flame monitor unit and starts a preglow time of approx. 30 s. After expiry of the preglow time, the stationary heater control unit actuates the fuel pump directly and the fuel feed starts. The fuel evaporates on a metallic mesh in the burner housing and forms a fuel/air mixture together with the combustion air, which ignites on the glow plug. A flame is produced which heats the coolant. During heating mode, the glow plug/flame monitor unit performs the function of the flame monitor.

If the flame monitor records an insufficient temperature (flame failure or insufficient flame formation), the stationary heater control unit switches off the stationary heater fuel pump. It then initiates a one-off re-start. If flame formation is still not possible, the stationary heater control unit switches off the stationary heater fuel pump and activates the emergency shutoff function with run-on of the combustion-air blower. A temperature sensor in the heater unit records the temperature in the heater unit. The stationary heater switches off from a temperature of approx. 125 °C. The stationary heater fuel pump also switches off from a temperature of approx. 145 °C.