Condensing Models: On-Demand Water Heater Service Handbook • 41
MAINTENANCE
Preparing the
New SECONDARY
Heat Exchanger
for Installa on
(Indoor Models)
NOTICE: Assembly of the secondary
heat exchanger is different for the
indoor and outdoor models.
1. Remove the following items from
the secondary heat exchanger,
then INSTALL THEM IN THE SAME
LOCATIONS ON THE NEW HEAT
EXCHANGER:
•
Flue gasket (item 154, p. 70) that
is located around the exhaust flue.
•
Exhaust high limit switch (item
466, p. 70): remove the two (2)
screws that are holding it in place.
•
Exhaust thermistor and gasket
(items 464 ,465, and 715 on
p. 70): one screw holds the
plate in place (item 053, p. 70).
•
Two (2) freeze protection heaters:
one is shaped as a long rod (item
413, p. 70) and located on
the front, left-hand side of the
assembly. The other is located on
the front, right-hand side of the
assembly (item 418, p. 70).
2. Complete the steps in “Installing
the Heat Exchanger (Indoor
Models).”
Installing the
Heat Exchanger
(Indoor Models)
1. Connect the primary and secondary
heat exchangers, making sure that
the
fl
ange on top of the primary heat
exchanger (male connector) goes into
the connec on on the bo om of the
secondary heat exchanger. The tube
from the primary heater will insert
into the back elbow on the secondary
heat exchanger (Figure 31, page 40).
2. Make sure that the screw holes
on the sides and back line up
properly. Insert and hand- ghten
all four (4) moun ng screws. See
Figure 34, page 41.
3. A ach fastener 14-22 (item 458, page
70) where the connec on tube
from the primary heat exchanger and
the back elbow on the secondary heat
exchanger meet. See Figure 32, page
40.
(“14-22” is marked on the end of this
clip; all such clips are marked on the
end in the same manner.)
4. Install the heat exchanger
assembly into the case, making
sure that the
fl
ue gasket
(item 154, p. 70) is on the inside
of the case.
5. Insert and hand ghten three (3)
screws as shown in Figure 30, page
39. This will secure the heat
exchanger assembly to the heater
case.
6. Install the burner into the combus on
chamber. (See page 70.) There are
grooves on the sides of the combus on
chamber; the bo om of the burner will
slide along the grooves.
6.1
Insert and hand ghten two
(2) screws below the burner,
at the back. (See Figure 29,
p. 39.) These screws will
secure to the back of the
Connector/
Nipple
Air Tube
Figure 33.
Example:
Install Screws at
Four Locations
Fourth
screw is
on
opposite
side
(not
shown)
Angled View of Primary and
Secondary Heat Exchangers
1
2
3
Figure 34.
