Bosch WFMC3200UC Training Manual page 71

71
WFMC Service Tips
WFMC Service Tips
Symptom
Drum won't rotate.
Washer won't heat.
WARNING!
before starting any repairs.
Problem
Drum rear bearing
has failed.
Motor control has
failed.
Drum drive motor
has failed.
Heater has failed.
NTC has failed.
Heater is covered
with scale.
Voltage too low.
Control module
has failed.
Unplug washer
-- Troubleshooting (2)
-- Troubleshooting (2)
Check how drum rotates.
replace outer tub (containing faulty rear bearings).
Check voltage at motor connectors when motor is energized.
If low or no voltage, replace faulty motor control.
120V, check motor resistance (when washer de-energized). If
motor is OK, replace faulty motor control.
Check voltage at motor connectors when motor is energized. If
~ 120V, check motor resistance (when washer de-energized). If
motor faulty, replace faulty drum motor.
Disconnect heater and measure resistance at terminals (~ 13.7 –
15.2 Ω). Replace heater if faulty.
Disconnect NTC and measure resistance at terminals (~ 22.8 –
27.4 k Ω @ 20ºC (68ºF)). Replace NTC if faulty.
If possible, remove & clean heater. If not, replace it.
Have an electrician check the house wiring and the wiring to the
washer to make sure it is 120 volts.
Check voltage output to drain pump when it's energized. If no
voltage, replace faulty control module.
HINT:
problems quickly and thoroughly where resistance
measurements usually aren't needed.
Solution
If drum wobbles or won't move,
The washer test program diagnoses
1st Edition/Revision 6 (2/2/04)
If voltage ~