Flame Sensor; Temperature Limiter; Glow Plug; Dosing Pump - Webasto HL 90 Owner's Manual

2 General Description
2.4

Flame Sensor

The flame sensor is a photo transistor changing its
resistance depending on the flame intensity. The signals
are supplied to the control unit for processing.The flame
sensor continuously monitors the flame condition during
heater operation.
2.5

Glow Plug

The glow plug ignites the fuel/air mixture during heater
start. The glow plug voltage is 4.2 Volts.
202
2.6

Temperature Limiter

The temperature limiter protects the heater against undue
high operating temperatures. The temperature limiter
responds at a temperature in excess of 175° C to
disconnect the electrical circuit and switch off the heater
with a run-down.
After the temperature limiter has cooled down, it may be
reset by pressing the reset pin. The heater may then be
switched on again.
Reset Pin
2.7

Dosing Pump

The dosing pump is a combined delivery, dosing and
shut-off system for the fuel supply of the heater out of the
vehicle fuel tank.
Dosing Pump DP 2
Dosing Pump DP 30
HL 90