Webasto DBW 2010 Service And Repair Manual

Webasto Product N.A., Inc. 26 www.techwebasto.com
TROUBLESHOOTING DBW 2010/2020/300 COOLANT HEATERS
5.3 INSTRUCTIONS FOR FAULT FINDING
5.3.1 COMBUSTION STARTS IMMEDIATELY WHEN HEATER IS SWITCHED ON
5.3.2 H
EATER DOES NOT START WHEN SWITCHED ON
YES
NO
Electronic control unit
defective
Voltage on terminal
B1, B2 and B4?
Are electric fuses
defective?
Volume on control
thermostat?
Volume on control
thermostat after
cooling of coolant
in the cycle?
Control thermostat
defective?
Are electric fuses
defective?
Replace fuses and
switch heater ON;
does fuse release?
Feed connection
defective
Temperature in the
cooling cycle too high
Voltage too low?
< 18 ± 1V resp.
< 9 ± 0.5V
Voltage on motor? Voltage across
terminal C2 and C5
of control unit?
Under-voltage
protection in the
control unit has
reacted; charge battery
Control unit defective,
replace.
Check feed
connections to motor
for circuit interruptions
Is the large spur gear
easily spun?
Fuel pump defective;
replace fuel pump
Motor defective;
internal fault
Replace defective fan
shaft bearings / parts
Is the motor easy to
spin up?
Is the motor easy to
spin up with the nozzle
holder plate removed?
Is the motor shaft easy
to spin up when
removed from
mounting?
Motor defective;
internal fault
Motor defective;
internal fault

Webasto DBW 2010 Specifications

General

Brand	Webasto
Model	DBW 2010
Category	Water Heater
Language	English