Bosch Integra 500 Series Technical Service Bulletin page 2

Technical Service Bulletin
Removing the Heat Exchanger
Models 2400ES, 2700ES, Evolution 500, and 715ES:
see bulletin TWH-G3-22 "Replacing Copper Heat Exchanger"

Models 830ES, 940ES, and 940ESO:
 see Therm Bulletin "Replacing Copper Heat Exchanger"
Models C800ES, Integra 500, and C920ES/ESC:
see bulletin TWH-G3-21 "Replacing & Servicing the Condensing

Heat Exchanger"
see bulletin TWH-G3-22 "Replacing Copper Heat Exchanger"

Models C950ES, C1050ES, and C1210ES/ESC
see Therm Bulletin "Replacing & Servicing the Condensing Heat

Exchanger"
 see Therm Bulletin "Replacing Copper Heat Exchanger"
Removing gas valve and gas/air mixer
1. Unplug wire connection from gas valve (Fig. 3, pos. 1).
2. Disconnect clear silicone pressure balance tube from right side
of gas valve. (Fig. 3, pos. 2)
3. Loosen and disconnect large 30mm hex nut on the left side of
gas valve (Fig. 3, pos. 3).
4. Remove 3 Phillips head screws on the black plastic air supply
duct and remove this component (Fig. 3, step 4).
5 5
5. Remove 4 Phillips head screws that attached the gas/air mixer
to the primary fan (Fig. 3, step 4).
6. Remove the gas valve and gas/air mixer as one piece
Data subject to change without notice | Printed in the USA | BTC 740002329 A | 05.2014
Removing secondary fan
1. Unplug wire connections into the secondary fan (Fig. 4, pos. 1).
2. Remove 2 Phillips head screws from the top of the secondary
fan (Fig. 4, pos. 2).
3. Secondary fan will drop down once second screw is removed.
The fan can now be removed.
Figure 3
Removing primary fan and burner
6 6
1. Unplug wire connection on the back left of the primary fan.
5 5 2. Disconnect the back fl ow sensor on the front of the burner
(Fig. 3, pos. 6).
3. Remove 2 Phillips head screws from the burner retaining plate
left and right (Fig. 3, pos. 5).
4. Burner tray and primary fan can now be removed as one piece.
Extreme care must be taken with the Ceramat burner. This is
a fi berglass mat. Take care not to touch or poke the burner
mat material as any damage will require a complete new
burner tray to be installed.
5. Using an 8mm wrench, remove the 4 nuts that secure the
primary fan to the burner.
6. Separate the burner from the primary fan and replace fan or
burner.
Replacing Primary Fan & Main Burner | 2
Bosch Thermotechnology Corp.
Figure 4