NGW 300 / LGW 300 / GBW 300
8 Servicing work
805
8.7
Disassembly and installation
ATTENTION
In its installed state, only the following disassembly and
dismantling procedures are permissible, provided that
thereis adequate room available for disassembly:
–
Replacing the temperature limiter
–
Replacing the regulating thermostat
–
Replacing the control unit
–
Replacing the gas pressure regulator
8.7.1 Dismantling and installation of the heater
8.7.1.1 Disassembly
1. Disconnect the wire harness plug connection to the
vehicle and to the circulating pump.
2
If present, loosen the gripping clamp at the exhaust
outlet.
3. Dismount the suction line for the gas delivery at the
burner head and seal with blind plugs.
4. Remove the reference pressure line at the burner
head, if present.
5. Drain pressure from the coolant circuit.
6. Close the water cock, if present.
7. Loosen the hose clamps on the coolant hoses.
Remove the hoses and seal with blind plugs.
8. Remove 4 screws and flat washers or 4 screws and
nuts from the heater bracket.
9. Remove the heater.
8.7.1.2 Installation
1. Bring the heater into the installation position and
attach with 4 screws and flat washers or 4 screws and
nuts (tightening torque of 15 +5 Nm).
2
If there is an exhaust line, secure it with a gripping
clamp at the exhaust outlet.
3. Mount the coolant hoses and secure with hose
clamps.
4. Open the water cocks, if present.
5. Mount the suction line for the gas deliveryand the
reference pressure line.
6. Connect the wire harness plugs to the vehicle and at
the circulating pump.
7. Replenish the coolant and bleed the coolant circuit.
ATTENTION
Due to the rise in pressure, operating the heater when the
water cocks are closed will cause the connecting hoses to
burst and the heat exchanger to be damaged.
8.7.2 Replacing the temperature limiter
PLEASE NOTE
The same procedure is followed when replacing the
temperature limiter whether the heater is installed or not.
The replacement must be carried out in accordance with
9.2.1.
8.7.3 Replacing the regulating thermostat
PLEASE NOTE
The same procedure is followed when replacing the
regulating thermostat, whether the heater is installed or not.
The replacement must be done in accordance with 9.2.2.
8.7.4 Replacing the SG 1585 control unit
PLEASE NOTE
The same procedure is followed when replacing the
control unit whether the heater is installed or not.
The replacement must be done in accordance with 9.2.3.
8.7.5 Dismantling and installation of the gas
pressure regulator
Replacing the gas pressure regulator must be done in
accordance with 9.2.1.1.
