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

Model All (4xWD) 

Model All (CAR) 

Example illustration of stationary heater unit 

Courtesy of MERCEDES-BENZ USA

Overview 

This document contains information on:

• General 
• Function requirements 
• Function 

General 

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

Function requirements 

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

Function 

The stationary heater control unit (1.1) starts the heating mode by actuating the combustion-air blower (1.2) in the heater (1). 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 (1.1) actuates the fuel pump directly and the fuel feed starts. The fuel evaporates on a metallic mesh in the burner housing (1.3) and, together with the combustion air, forms a fuel/air mixture, 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 detects an insufficient temperature (flame failure or insufficient flame formation), the stationary heater control unit (1.1) 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 (1.1) switches off the stationary heater fuel pump and activates the emergency shutoff function with run-on of the combustion-air blower (1.2).

A temperature sensor in the heater (1) measures the temperature in the heater (1). 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.