Burner Removal And Installation; Removal - A.O. Smith ATI-140H-N Service Handbook

•
Outdoor Models:
There are three (3)
receptacles on the
computer board that will
be open (Figure 65).
•
Item "I" in the schematic
(p. 22) uses a separate
wiring assembly which
includes three wires:
yellow, green, and
orange.) Install it as
shown in the schematic.
5.2 Use screws to secure
three (3) green wires to
the bo om, center of the
manifold plate. See "Ground
Connec ons" in Figure 25,
page 36. (There are two
moun ng holes for these
wires.) The three green
wires can be iden fi ed as
follows:
•
One green wire comes
from the power cord.
•
Two green wires come
from connectors on the
computer board.
5.3 If necessary, complete the
wiring connec ons inside the
cabinet:
•
Locate the plug and
receptacle with blue
wires. (They are at the
mid-center of the cabinet,
on the right-hand side.)
Plug them together.
•
FOR INDOOR MODEL
ONLY: Locate the plug
and receptacle with
yellow wires. Plug them
together.
5.4 FOR INDOOR MODEL ONLY:
Plug the wires from the
temperature controller (item
721, p. 67) to the matching
56 • Condensing Models: On-Demand Water Heater Service Handbook
wires from the computer
board. (These wires are
black and white).
6. Restore power to the water heater.
7. Open the gas valve slowly,
checking for leaks. If gas leaks
appear, shut off the gas supply and
disconnect power to the water
heater.
8. Turn on water to the heater and
test for proper opera on.
9. Verify that there are no water or
gas leaks. Correct any leaks that
are found.
10. Reinstall the front cover. (If yours
is an indoor model, install the
front cover a er inser ng the
temperature controller into its
opening fi rst.)
If you have any questions, please
contact technical support.
Burner Removal
and Installa on
Tools:
●
#2 Phillips Screw Driver

Removal

1. Shut off Power by disconnec ng
the power cord or shu ng off the
power disconnect.
2. Shut off the gas supply to the
heater.
OPEN CONNECTORS ON THE COMPUTER BOARD:
• TWO FOR INDOOR MODELS
• THREE FOR OUTDOOR MODELS
TWO OPEN
(OUTDOOR MODELS)
(ALL MODELS)
Figure 65.
•
3. FOR INDOOR MODELS ONLY:
Remove the Temperature
Controller (item 721, p. 67)
by disconnec ng it at the white
connector.
4. Remove the computer board
(PCB). See item 701, p. 68). See
also Figure 24, page 35.
4.1 Disconnect all of the wires
from the PCB.
4.2 Remove the screw at the top,
then remove the board. (If
necessary, refer to Figure 62,
page 52).
5. Remove the fuse box assembly
(items 703 & 120; page 68):
5.1 Disconnect the connector at
the top port which comes
from the main power supply.
OPEN