Models: 715ES, C800ES, 2400ES, 2700ES, Evolution 500, Integra 500

Replacing the control unit

Service Bulletin G3-24

Introduction

Tools needed:

Phillips head screw driver Small flat head screw driver Needle-nosed pliers

Note: Avoid touching printed circuit board (PCB) as static discharge may damage circuitry.

Preparation

Push power button to “OFF” and unplug power cord.

Loosen two Phillips head screws on bottom rear of front cover. Pull cover bottom outwards then lift cover upwards to remove.

Removing control unit

Remove three Phillips screws on front of control unit. (Fig. 2, pos. 1)

Turn control unit to expose the rear. (Fig. 2, pos. 2).

Locate and remove 6 Phillips head screws on back of control unit (Fig. 2, pos. 3).

control unit front

33

control unit front

33

Figure 2

Remove rear cover from control unit to expose circuit board electrical connections. Slide wire restraints out of control unit.(Fig. 3, pos. 1).

Remove two large electrical strip connectors by pulling them away from board. (Fig. 3, pos. 2).

Remove medium sized electrical strip connector by pulling it outwards. (Fig. 3, pos. 3).

Remove small electrical strip connector by pulling it outwards. (Fig. 3, pos. 4).

Remove two large ignition wires by pulling them outwards. (Fig. 3, pos. 5).

Remove yellow/green striped ground wire spade connection by depressing tab on connector and pulling it gently off the board. (Fig. 3, pos. 6).

Loosen two small flat head screws on terminal block for power cord. Pull black and white wires free from terminal block and control unit. (Fig. 3, pos. 7).

Loosen Phillips head screw and remove green ground wire con-nection for power cord. (Fig. 3, pos. 8).

Figure 3

1 1 1

22 34 56

7

8

Remove control unit from the water heater.

Appliance evaluation for PCB jumper location

Please evaluate the following prior to installation of the replacement PCB:

2 | G3-24 | 715ES, C800ES, 2400ES, 2700ES, Evolution 500, Integra 500 Service bulletin

Data subject to change without notice | Printed in the USA | BTC 710002318 D | 06.2012 Bosch Thermotechnology Corp.

Bosch Thermotechnology Corp.50 Wentworth AvenueLondonderry, NH 03053

Tel: 1-800-642-3111Fax: 1-603-965-7581www.bosch-climate.us

Locate rating plate sticker on right side of heater cover. Determine model number (Fig.1, pos.A) and gas type (Fig.1, pos.B).

Figure 1

PCB jumper installation

In order for the appliance to work correctly, the proper jumpers must be installed on the PCB board. (Fig.4)

Backside of control unitBackside of control unit

Figure 4

Based on your model and gas type, jumpers should be installed on the PCB in the following arrangement:

Model 2400 ES:

Natural Gas

NaturalGas

Figure 5

Liquid Propane

Models: C 1050 ES, 940 ES/ESO, 2700 ES, C 800 ES, 715 ES, Evolution 500 (WTD 27), or Integra 500 (WTD 30)

Figure 7

Natural Gas

Liquid Propane

Replacing control unit

Once the appropriate jumpers have been determined, remove rear cover of replacement control unit.

Install jumpers in the proper location on PCB.

Connect green ground wire from power cord to replacement control board with Phillips head screw. (Fig. 3, pos. 8).

Reconnect black and white power cord wires to terminal block on replacement control unit; Black -L (Load), White - N (Neutral). Secure to terminal block by tightening flat head screws. (Fig. 3, pos. 7).5. Reconnect yellow/green striped ground wire to spade connection on replacement control board. (Fig. 3, pos. 6).

Reattach large ignition wires to replacement control board (no polarity). (Fig. 3, pos. 5).

Reconnect small electrical strip connector to replacement con-trol board. (Fig. 3, pos. 4).

Reconnect medium sized electrical strip connector to replace-ment control board. (Fig. 3, pos. 3).

Reconnect two large electrical strip connectors to replacement control board. (Fig. 3, pos. 2).

Reseat rubber wire restraints in control unit. (Fig. 3, pos. 1).

Replace rear cover on unit using 6 Phillips screw (Fig. 2, pos.3).

Place control unit back into water heater and secure with 3 Phillips head screws. (Fig. 2, pos. 1).

Plug water heater power cord back into electrical outlet and push On/Off button on water heater to “ON”.