Bosch 425HN Reference manual

Service bulletin

Replacing control box

CT-27 | 1600H, 425HN

Tools needed:

Phillips head screwdriver

Needle-nosed pliers

Removing ignition unit

1. Close installer supplied cold water shut off valve to water heater.

2. Remove front cover of heater. (See instructions in the installa-

tion manual)

3. Remove single ignition wire connection (to spark electrode)

from upper left corner of ignition unit. Unclip wire from bracket

on top of ignition unit (425HN models only). (See Fig. 1)

4. Remove multiple wire connector from lower right corner of

ignition unit by gently pulling outwards with needle-nosed pliers.

(See Fig. 1)

5. Remove screw with ground wire connection from upper right

corner of ignition unit Metal bracket and ignition unit will drop

out of heater.

6. Remove ignition unit from metal bracket.

Control box (425HN model shown) Figure 1

Installing ignition unit

1. Insert tab on lower left of ignition unit into slot in lower left of

metal bracket.

2. Mount ignition unit with bracket to heater by inserting screw

into upper right hand corner.

Note: Feed screw through ground wire eyelet with washer before

threading through ignition unit to heater. (See Fig. 1)

3. Press multiple wire connector into lower right of ignition unit.

4. Push ignition wire on to single terminal in top left corner of

ignition unit. Clip wire into bracket on top of ignition unit

(425HN models only).

5. If a replacement hydro generator (black and red lead wires) was

sent as a temporary solution for ignition failure, please reinstall

original hydro generator, part# 8707406071 (blue and brown

lead wires).

6. Install front cover, open cold water supply and return heater to

service.

1 2 |TWH-G2-06 | 2400E, 2400EO, 635ES, 635ESO, 250SX, 250SXO Service bulletin

Data subject to change without notice | Printed in the USA | 1.2007 Bosch Water Heating

BBT North America Corporation

Bosch Group

Bosch Water Heating

340 Mad River Park

Waitseld, VT 05673

Telephone 800-642-3111

Fax (802) 496-6924

techsupport@boschhotwater.com

This manual suits for next models

2

Other Bosch Water Heater manuals

Bosch

Bosch Therm 4300 Series Guide

Bosch

Bosch TR1000 4 T User manual

Bosch

Bosch GWH 10-2 G Series Technical Document

Bosch

Bosch Stora WS 300-5 PK Operating instructions

Bosch

Bosch AquaStar 250SX NG User manual

Bosch

Bosch WR430-7K Assembly instructions

Bosch

Bosch Highflow 17e User manual

Bosch

Bosch BBT NORTH AMERICA AquaStar 240FX Service manual

Bosch

Bosch AquaStar 125X LP User manual

Bosch

Bosch C950ES Reference manual

Bosch

Bosch 715ES Reference manual

Bosch

Bosch TR3500T Series User manual

Bosch

Bosch 125B LP User manual

Bosch

Bosch WT 11 AM1 E Guide

Bosch

Bosch C1210ES User manual

Bosch

Bosch TR5000R 24/27 EB User manual

Bosch

Bosch C 1210 ES/ESC User manual

Bosch

Bosch W 125 T1 Installation and operation manual

Bosch

Bosch 830ES User manual

Bosch

Bosch C950ES User manual

Bosch

Bosch BSS250E-2 User manual

Bosch

Bosch Tronic 5000C Reference manual

Bosch

Bosch TR7000R Series User manual

Bosch

Bosch TR8500 15/18 DESOB User manual

Popular Water Heater manuals by other brands

Kenmore

Kenmore 153.582400 Use & care guide

Applimo

Applimo Edel AIR Installation and operating instructions

STIEBEL ELTRON

STIEBEL ELTRON Eltronom SHU 5 S Operating and installation instructions

clage

clage E-Mini Series Operating and installation instructions

Toyotomi

Toyotomi Oil Miser OM-180 installation manual

Bradford White

Bradford White EF Series Service manual

Eccotemp

Eccotemp 40-H Use & care manual

Dimplex

Dimplex ECSd125-580 Installation and user instructions

Dux

Dux 32FCR6N installation manual

Toyotomi

Toyotomi Oil Miser OM-148 (Type D) Operation and maintenance instructions

Noritz

Noritz N-132M Owner's guide and installation manual

TESY

TESY GCV7/4S 10047 Instructions for use and maintenance

A.O. Smith

A.O. Smith Gphe 50 instruction manual

Koryo

Koryo KWHZF15Y user manual

Pentair

Pentair PSC-14-4-02 Installation and operation manual

GE

GE 40M06AAG Energy guide

Thermor

Thermor AEROMAX SPLIT 2 Instructions for use

American Hometec

American Hometec AHQ-B03X Installation and operation manual