Webasto Thermo 90 Installation Instructions

Initial Operation
After the heater has been installed, the water circuit and
the fuel supply system must be thoroughly bled. When so
doing, the vehicle manufacturer’s instructions must be ad-
hered to.
During a test run of the heater, all water and fuel connec-
tions must be checked for leakage and security. Should
the heater shut down during operation, troubleshooting ac-
tivities must be carried out.
Malfunctions
Fault Shutdown
If the flame fails to materialize fuel is delivered for max.
180 seconds.
If the flame is extinguished during operation fuel is de-
livered for max. 90 seconds.
In the event of overheating (tripping of temperature
limiter) no fuel is delivered.
In the event of a shutdown initiated by the undervoltage
protection device
Thermo 90 Thermo 90 S
12 volts 10,5V  0,5V 10,5V – 0,5V
24 volts 21V  1V 21V – 1V
for more than 20 seconds,no fuel is delivered.
After the cause of malfunction has been eliminated, inter-
lock deactivation is to be performed by switching the
heater off and then back on. If an overheating condition
has occurred the pushbutton of the temperature limiter
must be reset.
Diagnosis in the Event of a Fault Shutdown of Thermo 90
Check fuses and electrical connections.
If the heater is activated by the switch or the timer with 3
time settings, the different types of malfunctions are indi-
cated by coded flashing signals via the operation indicator
light during the after-run period of the heater.
After five short signals have been emitted, the long flash-
ing pulses can be counted:
1x No start (after 2 start-up attempts)
2x Flame extinction (recurrent >5)
3x Undervoltage
4x Premature flame detection
5x Flame detector interruption or
flame detector short circuit
6x Temperature sensor interruption or
temperature sensor short circuit
7x Metering pump interruption or
metering pump short circuit
8x Blower motor interruption or
blower motor short circuit
blower motor incorrect speed
9x Pencil-type glow plug interruption or
pencil-type glow plug short circuit
Thermo 90 / Thermo 90 S
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Webasto Thermo 90 Specifications

General

Brand	Webasto
Model	Thermo 90
Category	Water Heater
Language	English