Rinnai Circ-Logic RU80e, Service Manual

Page: 32 / 60

Condensing Water Heater Service Manual 32
100000354
KA Series Component Replacement Instructions
RC80HPe
Heat Exchanger
18. Disconnect condensate tube from upper heat
exchanger.
Disconnect wire harnesses
19. Disconnect heat exchanger thermistor (upper right).
20. Disconnect anti frost heater connector at bottom of
cabinet. One blue connector.
21. Disconnect thermal fuse harnesses (lower right).
Two single white wire connectors.
Remove heat exchanger
22. Remove three screws at bottom of heat exchanger.
Remove two screws at top back of heat exchanger.
Remove two screws at top on reinforcement bracket
for upper heat exchanger.
23. Remove heat exchanger assembly.
24. If replacing the upper (secondary) heat
exchanger,
remove clips from two upper heat
exchanger copper pipes. Disconnect pipes.
Remove eight screws from flue outlet assembly.
Discard screws.
Remove two screws from reinforcement bracket.
Discard screws.
25. Remove three screws on front where upper and
lower heat exchangers meet. Discard screws. Turn
heat exchanger over; remove six screws on back
where upper and lower heat exchangers meet.
Discard screws. Separate the upper heat exchanger
from the lower heat exchanger.
Installation
26. Install new gasket from kit onto the upper heat
exchanger. (Remove the old gasket if the upper
heat exchanger is not new.) Attach upper heat
exchanger to lower heat exchanger with new
screws from kit. (six screws on back, three screw on
front)
27. If replacing lower (primary) heat exchanger,
transfer wiring from old heat exchanger to new heat
exchanger. Ensure proper routing of harnesses.
These include thermal fuse, bi
-
metal, heat
exchanger thermistor, and ceramic heaters.
28. Transfer parts from old heat exchanger to new heat
exchanger.
29. If replacing the upper (secondary) heat
exchanger,
install connecting pipe to upper heat
exchanger and copper tee with new o
-
ring and clip;
and connecting pipe between upper heat
exchanger and bypass valve with new o
-
ring and
clip.
Install the flue outlet assembly (8 screws) and the
reinforcement bracket (2 screws).
Upper (secondary)
heat exchanger
Lower (primary)
heat exchanger
Thermistor
(Step 19)
Flue outlet
(Step 24)
Condensate tube clip
(Step 18)