517
Thermo plus 160/230/300/350 5 Troubleshooting
Manual inspection
• Remove burner head (see 8.2).
• Disconnect the solenoid valve plug from the control
device.
• Check the electrical functionality by applying direct
voltage:
– Opening voltage: starting at 17.0 Volt
– Power consumption at
24V and 20°C: 9 Watt
– Nominal current at 24V: 0.37 Ampere
The solenoid valve must audibly open, when voltage
is applied.
• Connect the solenoid valve plug to the control device.
• Install burner head (see 8.2).
5.6.12 Nozzle block preheater inspection
The heating element of the nozzle block preheater can
heat up during inspection.
Do not pull heating element out of the nozzle holder
during inspection.
NOTE:
At a temperature of < 5°C the thermostat switches the
heating element on (see 3.1.5).
The power consumption of the heating element at 24V is
approx. 80W.
Inspection using the STT diagnosis
• Remove burner head (see 8.2).
• Connect the test plug instead of the temperature
sensor plug to the control device.
• Reconnect the heater with the vehicle electrical
system.
• Connect the STT diagnosis to the heater.
• Start STT diagnosis, establish connection to the
heater and open the Component Test menu.
• Select the nozzle block preheater in the Component
Test menu, enter a runtime and then start the compo-
nent test.
In order to heat up the heating element, a temperature
below 5°C must be applied to the thermostat. If neces-
sary, the thermostat must be cooled below 5°C for the
test.
Caution: At the same time, when a circulating pump is
connected, it is started too.
Nominal condition: The heating element warms up.
• After the test is completed, exit STT diagnosis as
needed.
• Disconnect the heater from the vehicle electrical
system (Observe 5.2 !).
• Remove the test plug.
• Install burner head (see 8.2).
Manual inspection
• Remove burner head (see 8.2).
• Disconnect the nozzle block preheater plug from the
control unit.
• If necessary, remove the nozzle block preheater.
• Bypass the thermostat or if necessary cool it down
below 5°C.
• Connect an ohmmeter to the connector.
Resistance is max. 8 Ohm
• If necessary install the nozzle block preheater.
• Plug the nozzle block preheater into the control
device.
• Install the burner head (see 8.2).
Fig. 512 Solenoid valve
Risk of burns!
Caution!
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