GF83.70-D-4202H STH Heater Unit, Component Description

GF83.70-D-4202H STH Heater Unit, Component Description
MODEL 906.111 /113 /131 /133 /135 /153 /155 /211 /213 /231 /233 /235 /253 /255 /611 /613 /631 /633 /635 /637 /653 /655 /657 /711 /713 /731 /733 /735
- with CODE (H12) Warm water auxiliary heater

MODEL 906.611 /613 /631 /633 /635 /637 /653 /655 /657 /711 /713 /731 /733 /735
- with CODE (HZ5) 10 kW warm water auxiliary heater with timer







1 Stationary heater unit

Location
The stationary heater unit is located on the vehicle underside between the left vehicle rocker panel and the vehicle tank on the level of the B-pillar.

Task
When the engine is stopped ("circuit 61 OFF"), the stationary heater unit generates the heat needed to warm up the interior compartment by stationary heater (STH) operation.
When the engine is running ("circuit 61 ON"), the stationary heater unit generates the heat needed to warm up the interior compartment by heater booster (ZUH) operation.







Design
1 Stationary heater unit
2 Casing
3 Combustion air blower with blower motor (N33/3m1)
4 Cover of combustion air blower with blower motor (N33/3m1) (3)
5 Combustor with downpipe
6 Heat exchanger
7 Cover of blower motor (N33/3m1)
8 Cover for casing (2)
9 Coolant inlet connection
10 Coolant outlet connection
11 Gasket between casing (2) and combustion air blower with blower motor (N33/3m1) (3)
12 Fitting for glow pin (N33/3r1) with fuel feed line
13 Gasket between combustor with downpipe (5) and combustion air blower with blower motor (N33/3m1) (3)
14 O-ring
15 Soft trim with O-rings for the fitting of the glow pin (N33/3r1) with fuel feed line (12)
16 Bracket for fitting of glow pin (N33/3r1) with fuel feed line (12)
17 14-pin connector for warm water auxiliary heating control unit (N33/3)
18 Line for circulation pump (M13/4)
19 Push spring for temperature sensor (N33/3b1) and overheating sensor (N33/3b3)
N33/3 Warm water additional heater control unit
N33/3b1 Temperature sensor
N33/3b2 Flame sensor
N33/3b3 Overheating sensor
N33/3m1 Blower motor
N33/3r1 Glow pin