Bosch TRONIC 5000C Pro WH17 Technical Service Bulletin

Technical Service Bulletin:
Triac Printed Circuit Board Replacement
TRONIC 5000C Pro Models: WH17, WH27, WH36
Introduction
WARNING
ELECTRICITY IS EXTREMELY DANGEROUS.
TAKE EXTRA PRECAUTIONS AND ENSURE ALL
CIRCUIT BREAKERS ARE OFF BEFORE
PERFORMING ANY WORK ON THE HEATER
WARNING
THE FOLLOWING PROCEDURE MUST BE
PERFORMED BY A LICENSED ELECTRICIAN
Tools Required
 Electrical meter
Phillips head screwdriver

 Small flat head screwdriver
Heat sink paste

Replacement of the triac printed circuit board will be
easier if you can work slightly above the unit.
Preparation
1. Remove the four cover screws and retain, lift off the cover and
store safely.
2. Using an electrical meter, confi rm power is off the the heater.
Removing the triac wiring
1. Remove the thin white signal wires from the printed circuit
boards by gently bending the locking tab on the connector with
a small fl at head screwdriver so that the plug can be removed
(Fig. 1). These cables can be moved out of the working area.
2. Using the small fl at head screwdriver pull the ¼" push on
connectors off the triac printed circuit boards (Fig. 2). The
recommended method is to use a small fl at head screwdriver in
the rectangular hole and then push the screwdriver blade so that
the connector pulls off straight.
Fig. 1
Fig. 2