A.O. Smith ATI-140H-N Service Handbook page 58

Figure 69.
Front View of Burner Assembly
Three Screws Three Screws
Area Beneath Burner (Inside Cavity)
Two Screws
8.10 Disconnect the solenoid
connectors (Item 707, p.
69) from the gas valve.
(There are three connectors.)
8.11 Inspect the gaskets on the
manifold plate for any tears.
If compromised, replace with
Manifold Screws:
• DO NOT remove the screws
shown below (indicated by
white, crossed-out circles).
• Remove the remaining
screws along the outside
edge (except as indicated).
Figure 70.
58 • Condensing Models: On-Demand Water Heater Service Handbook
part number 319143-044
(item 113) and/or 319143-
045 (item 114). See page
69.
8.12 Inspect the o-ring (item 151,
p. 69) and gas inlet ring
(item 119, p. 69) on the gas
connec on for cuts or breaks.
If damaged, replace with part
number 319143-057 (item 151)
and/or 319143-049 (item 119).
See page 69.
9. Remove the burner from the
combus on chamber:
9.1 Remove three screws across
the front of the burner
(Figure 69). DO NOT remove
the screws around the fl ame
sensor/AFR and igniter rods.
9.2 Remove two screws below
the burner, at the back
(Figure 69).
9.3 Slide the burner out toward
you. If it is diffi cult to
remove, try the following:
1.) Grasp an oval air vent
on the front of the burner
(at the edge on either
side). 2.) Pull fi rmly while
pushing on the bo om of
the combus on chamber to
provide leverage.
3.) Repeat on the opposite
side. 4.) Pull from the center.
It should slide out easily.
9.4 Check the gaskets on the
burner for tears. If the
gaskets are compromised,
replace with part number
319143-032.
Figure 71.
Install Plugs into Receptacles
(Yellow Wires)
(Yellow Wires)
Fuse Box
Location
Figure 72.
Terminals
Solenoid (SV3)
Manifold
Plate
Receptacles
(2)
Plugs (2)
Manifold
Plate