Bosch Integra 500 Series Technical Service Bulletin page 3

3 | Replacing Primary Fan & Main Burner
Reinstalling primary fan and burner
1. Attach the burner to the primary fan and ensure gasket is in
place.
2. This gasket can be reused.
3. Using an 8mm wrench, secure the 4 nuts to secure the primary
fan to the burner.
4. Burner tray and primary fan can now be reinstalled as one
piece.
5. Insert the 2 Phillips head screws into the burner retaining plate
(Fig. 3, pos. 5).
6. Reconnect the back fl ow sensor on the front of the burner
retaining plate.
7. Plug wire connection into the back left of the primary fan.
Reinstalling secondary fan
1. Insert tab on the back of secondary fan into bracket of burner
and then lift fan to align holes with the retaining bracket.
2. Insert the left Phillips head screw to secure fan and then insert
right Phillips head screw with secondary fan in place.
3. Plug wire connections into the secondary fan (Fig. 4, pos. 1).
Reinstalling gas valve and gas/air mixer
1. Install the gas valve and gas/air mixer as one piece.
2. Insert 4 Phillips head screws to secure the gas/air mixer to the
primary fan (Fig. 3, step 4).
3. Attach black plastic air supply duct and secure with 3 Phillips
head screws (Fig. 3, step 4).
4. Thread and tighten the large 30mm hex nut on the left side of
gas valve (Fig. 3, pos. 3).
5. Insert pressure balance tube on to brass nipple on right side of
the gas valve (Fig. 3, pos. 2).
6. Plug 4 wire connection into gas valve (Fig. 3, pos. 1).
7. Secure the control unit using the 3 Phillips head screws (Fig. 2,
step 1).
Reinstalling the Heat Exchanger
Reference appropriate bulletin(s) used for removal of copper
heat exchanger and/or secondary heat exchanger.
Data subject to change without notice | Printed in the USA | BTC 740002329 A | 05.2014
Placing the unit back into service
1. Slowly turn water on into the water to ensure all water
connections are secure. Search for any leaks on the pipe
connections.
2. Plug the water heater into the outlet and turn water heater on.
3. Turn the gas on to the water heater.
4. Install secondary combustion cover by uclipping two upper and
two lower clips to secure inner cover (Fig. 1, step 3).
5. Lift back corner of cover over tabs and lower into place (Fig. 1,
step 2).
6. Tighten two Phillips head screws located at bottom rear of
cover (Fig. 1, step 1).
Technical Service Bulletin
Bosch Thermotechnology Corp.
50 Wentworth Avenue
Londonderry, NH 03053
Tel: 1-800-283-3787
Fax: 1-603-965-7581
www.bosch-climate.us
Bosch Thermotechnology Corp.