A.O. Smith ATI-140H-N Service Handbook page 53

11. Install the fl ow sensor/control
valve (item 402, p. 70) and cold
connec on tube (item 462, p. 70)
as follows:
11.1 Insert the long, straight end of
the cold connec on tube into
the elbow on the secondary
heat exchanger. See connec on
point "B" on page 70 (shown
in two places).
11.2 Install the fl ow sensor/
control valve onto the inlet
water connec on (Figure 25,
page 36).
11.3 Insert the end of the cold
connec on tube into
the outlet of the fl ow
sensor/control valve. See
connec on point "D" on page
70 (shown in two places).
11.4 Install the fasteners:
•
One 16A fastener. See
item 459 on p. 70,
which secures the inlet of
the flow sensor/control
valve to the inlet water
connection. "16A" is
marked on the end of this
clip.
Install the clip as shown
in Figure 58.
•
Two 14-22 fasteners.
("14-22" is marked on the
end of each clip.)
See both instances of
item 458 on page 70.
These fasteners secure
the cold connection tube
at each end. Install as
described in Figure 60.
See also connection
points "B" and "D" on
page 70. The cold
connection tube's
brass rings must be
fully inserted at each
connection point.
11.5 Verify that all of the fasteners
on the water tubing are
installed properly
11.6 Install the cold water inlet
fi lter. (Refer to the water
heater's manual, if needed.)
11.7 Test for leaks by turning on
the water supply to the water
heater. Check the water tube
connec ons for any drips or
leaks. If any appear, turn off
the water, drain the water
heater, dry the components
that got wet, and fi x the leak.
12. Verify that the following pipe heaters
are installed. See the following pipe
heaters on page 70: item 413
(three instances) and item 414 (two
instances).
If installation is still needed,
12.1 Install the long pipe heater to
the bo om of the secondary
heat exchanger. (It will span
the front, le -hand side of the
primary heat exchanger as
shown in Figure 25, page 36.
See also item 413, page 70.
12.2 Install pipe heaters just below
connec on points "A" and "B."
(See page 70.) Secure each
one with a clip (item 451).
12.3 Install a pipe heater just above
connec on point "C." (See page
70.) Secure it with item 451.
12.4 Install a pipe heater to the
le of connec on point "D."
(See page 70.) Secure it
with item 451.
13. Install the fuse box assembly on
the le side of the manifold plate.
(See items 703 & 120, page 68;
Condensing Models: On-Demand Water Heater Service Handbook • 53
see also Figure 62.)
Hand ghten two screws to secure
it to the manifold plate.
14. Hook up the freeze protec on
heater wiring:
14.4.1 At the top of the fuse box
loca on, connect two plugs
and receptacles as described
in Figure 59.
NOTE: All connectors with
yellow wires are connected
to the same circuit, so the
order in which you connect
them does not ma er.
14.4.2 Below the fuse box loca on,
connect three plugs and
receptacles as shown in
Figure 61.
Secure these wires with the
cable clamp on the le side
of the cabinet.
15. Install the computer board (PCB):
•
Small feet at the bottom must fit
into the corresponding holes in
the case.
•
Insert the screw at the top of the
computer board, then hand-
tighten it to secure the board to
the fuse box assembly. See Figure
62.
15.1 Connect all of the wires to
the computer board. All
of the wire connectors are
uniquely sized and shaped
to fi t only in the correct
connector on the board.
If necessary, refer to the
schematic on page 22.
NOTE:
•
There are three (3)
receptacles on the
computer board that will
be open. See Figure 63.