40 • Condensing Models: On-Demand Water Heater Service Handbook
MAINTENANCE
13. Follow these steps to remove the
heat exchangers:
13.1 Slide the heat exchangers
down while gradually
angling the bo om toward
you.
13.2 Separate the primary and
secondary heat exchangers
as follows:
13.2.1 Remove fastener 14-22
(item 458, p. 70) from
the tube on the le -hand
side. (This tube connects
the primary heat exchanger
to the secondary heat
exchanger.)
13.2.2 Remove the four screws that
connect the primary and
secondary heat exchangers
(Figure 34).
13.3 IF you are replacing the
primary heat exchanger
assembly, go to “Preparing
the New Primary Heat
Exchanger for Installa on
(Indoor Models).”
IF you are replacing the
secondary heat exchanger
assembly Go to “Preparing
the New SECONDARY Heat
Exchanger for Installa on
(Indoor Models).”
Preparing the
New PRIMARY
Heat Exchanger
for Installa on
(Indoor Models)
The primary heat exchanger is the
same assembly for both indoor and
outdoor models. It comes with:
•
A combustion chamber attached
to the bottom of the heat
exchanger (See “Combustion
Chamber,” page 70)
•
A plate attached at the top with
a gasket surrounding the flue gas
connection to the secondary heat
exchanger. See “Heat Exchanger
(Primary)” on page 70.
1. Make sure the gasket on top of
the primary heat exchanger is
not compromised. If it is, contact
technical support.
2. Remove the following items from
the primary heat exchanger and
INSTALL THEM IN THE SAME
LOCATIONS ON THE NEW HEAT
EXCHANGER:
•
High limit switch on the right
side (item 411, p. 70).
•
Over-heat Cutoff Fuse (OHCF) (item
412, p. 70) and its five clips.
(Four clips are attached to the
primary heat exchanger and one is
attached to the outlet tube.) See
also Figure 24, page 35.
•
Air tube and its connector/nipple
on the bottom of the combustion
chamber. (See page 41, Figure
33.)
•
Two (2) freeze protection heaters
and clips; one is located on the
outlet tube near the bottom
and the other is located on
the connection tube from the
secondary heat exchanger. (See
items 413 and 414 on page 70.
See also page 39, Figure 28.)
•
O-Rings on the connection tubes:
Item 455 (p. 70) is attached
to the connection tube from the
secondary heat exchanger. Item
457 (p. 70) is attached where
the outlet water tube connects
to the outlet water connection.
(See connection points “A” and “C,”
p. 70).
CAUTION: these O-rings are
different sizes, so label them
and keep them separated.
3. Complete the steps in the next
sec on: “Preparing the New
SECONDARY Heat Exchanger for
Installa on (Indoor Models).”
Example:
with Clips
Insert tube into
black elbow.
Angled View of Primary and
Secondary Heat Exchangers
Figure 31.
TOP VIEW
• Wider span secures
black elbow.
• Narrow span
secures tube.
Narrow Span
Wider Span
Tube Fastener Installation
(Item 14-22)
Figure 32.
