Auxiliary Heater (ZHE), Function - GF83.70-S-0003TRA

Model 447.7 

With Code HZ1 (Auxiliary heater (warm air)) 

With Code ZH6 (Marco Polo ACTIVITY) 

Model 447.8 

With Code HZ1 (Auxiliary heater (warm air)) 

With Code ZK7 (Equipment line MARCO POLO) 

Auxiliary heater (ZHE), general 

The auxiliary heater (ZHE) (warm air stationary heater) mounted in the driver seat frame is operated in air recirculation mode. The air from the footwell in front of the front seats is drawn in by the heater through the air openings in the seat base and supplied to the heat exchanger.

The fuel is taken from the vehicle's on-board fuel tank. The combustion air drawn in from the outside and the fuel are mixed in the combustion chamber and ignited and combusted at the glow plug. In the process, the heat exchanger is heated and the intake air from the vehicle interior is warmed up at the hot outer walls. The heated air passes through the hot air outlet into the vehicle interior and flows in the direction of the sliding door.

Function sequence (With Code ZK7 (MARCO POLO equipment line)  )

The warm air stationary heater (WLSTH) control unit (N33/5) is controlled via operation at the central operating unit (COU [ZBE]) control unit (N10/16). Communication between the two control units occurs via the body manufacturer CAN (CAN MPM). A temperature sensor in the B-pillar paneling on the right records the interior temperature for controlling the auxiliary heater (ZHE). Control of the warm air stationary heater (WLSTH) control unit can also take place via the stationary heater timer (N34).

For both models, the warm air stationary heater radio remote control transmitter (A8/3) is available as special equipment (with code HY2 (Radio remote control for auxiliary air heater)). The button status of the warm air stationary heater radio remote control transmitter is received by the air stationary heater radio remote control receiver (A49/6) and forwarded to the warm air stationary heater (WLSTH) control unit, which actuates the corresponding function. The function of the warm air stationary heater radio remote control transmitter is described in the document "Auxiliary heater radio remote control transmitter, function".

• Starting procedure: 

  The maximum heat flux is reached in 45 s at the latest. If the flame does not materialize, a maximum of one additional start attempt may be automatically initiated. After a total fuel feed time of 90 seconds without flame formation, an emergency shutoff takes place.

• Power down: 

  A power down is carried out during all shutoff procedures (normal shutoff or emergency shutoff). The power down procedure for the combustion air blower involves a lower rpm as compared to wide open throttle operation.

• Restart after emergency shutoff: 

  After the trouble source has been rectified, the heater can be switched on via the central operating unit (COU [ZBE]) control unit. This does not apply after overheating has occurred in the heater.

	Auxiliary heater radio remote control transmitter, function	Model 447.7 with code HY2 (Radio remote control for auxiliary air heater) with code HZ1 (Auxiliary heater (warm air)) with code ZH6 (Marco Polo ACTIVITY) Model 447.8 with code HY2 (Radio remote control for auxiliary air heater) with code HZ1 (Auxiliary heater (warm air)) with code ZK7 (Equipment line MARCO POLO)	GF83.70-S-1000TRA
	Overview of system components for auxiliary heater		GF83.70-S-9993TRA