Bosch Integra 500 Series Reference manual

Technical Service Bulletin:
Replacing Primary Fan & Main Burner
Models: C1210ESC, C1210ES, C1050ES, C950ES, 940ES, 940ESO, 830ES, 2400ES,
2700ES, 715ES, C800ES, C920ES/ESC, Integra 500, Evolution 500
Introduction
This procedure must be performed by a qualified technician.
Tools needed:
Phillips head screwdriver
30mm open end wrench or large adjustable wrench
8mm open end wrench
Preparation
1. Use the power button on the front of the water heater to turn
the appliance off and then unplug from the electrical outlet.
Isolate the gas supply to the water heater by closing the
installer supplied gas shut-off valve.
2. Shut the inlet and outlet water supply off to the water heater
3. Drain the water from the water heater.
4. Loosen two Phillips head screws located at bottom rear of
cover. (Fig. 1, step 1).
5. Lift front cover upward and remove. (Fig. 1, step 2).
Step 1 Step 2
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Step 3Step
1
Step
2
2
0
6
44
9
56
-
11
.
1
V
Step
3
Figure 1
6. Remove combustion cover by unclipping two upper and two
lower clips securing cover. (Fig. 1, step 3)
7. Remove 3 Phillips screws on control unit (Fig. 2, step 1). Place
control unit into the service postion by engaging its tabs with
the holes in the horizontal sheet metal on bottom of the heater
chassis . (Fig. 2, step 2).
Step 2
Gas
Valve
S
te
p
2
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ve
Figure 2

Data subject to change without notice | Printed in the USA | BTC 740002329 A | 05.2014 Bosch Thermotechnology Corp.
Technical Service Bulletin Replacing Primary Fan & Main Burner | 2
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
6
5
5
6
Figure 3
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
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 4
Removing primary fan and burner
1. Unplug wire connection on the back left of the primary fan.
2. Disconnect the back flow 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 fiberglass 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.

Data subject to change without notice | Printed in the USA | BTC 740002329 A | 05.2014 Bosch Thermotechnology Corp.
Technical Service Bulletin
3 | Replacing Primary Fan & Main Burner
Bosch Thermotechnology Corp.
50 Wentworth Avenue
Londonderry, NH 03053
Tel: [phone]
Fax: [phone]
www.bosch-climate.us
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 flow 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.
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).