Rinnai REU-KA2530FFUD-US Service Manual page 48

KB Series Component Replacement Instructions
Heat Exchanger-Reassembly
19.The following parts must be transferred from the original primary and/or secondary heat exchanger(s) over to the
replacement:
heat exchanger thermistor, 3 Bi-Metal Over Heat Switches (the 3rd of which is 2 Bi-Metals on one harness),
Thermal Fuse, inlet connection pipe, heat exchanger connection pipe, secondary top plate (if steel heat exchanger
replaced) and ceramic heaters.
20.Attach primary heat exchanger to secondary heat exchanger using 14 screws. (These screws will have a white
coating and will be included in the replacement kit.) DO NOT USE THE ORIGINAL 14 SCREW WITH THE WHITE
COATING FROM ORIGINAL HEAT EXHANGERS. Be sure to use the new gasket(s) included in the replacement
kit. (FIGURE 12)
21.Attach burner assembly to primary heat exchanger using 15 screws. (These screws will have a white coating and
will be included in the replacement kit.) DO NOT USE THE ORIGINAL 14 SCREW WITH THE WHITE COATING
FROM ORIGINAL HEAT EXHANGERS. Be sure to use the new gasket(s) included in the replacement kit.
(FIGUREs 12 & 10)
22.Attach air box to rear of heat exchanger using 9 screws. (FIGURE 9)
23.Place heat exchanger assembly into cabinet of unit.
24.Attach bottom of heat exchanger to cabinet using 4 screws. (FIGURE 8)
25.Attach top of heat exchanger to cabinet using 6 screws. (FIGURE 7)
26.Secure copper drain tube to bottom of unit using 2 screws. Reconnect drain line (if applicable) to drain tube.
(FIGURE 6)
27.Attach rubber hose connection to condensate trap using clamp to secure. (FIGURE 5)
28.Attach inlet water lines to by-pass fitting using the retainer clips to secure them. Use 2 screws to secure the retainer
clips in place. (FIGURE 5)
29.Attach gas line to gas connection using the retainer clip to secure it. Use 2 screws (mechanical screws) to secure
retainer clip in place. (FIGURE 5)
30.Attach outlet water line to fitting using retainer clip to secure it. Use 1 screw to secure retainer clip into place.
(FIGURE 4)
31.Connect thermal fuse harness, heat exchanger thermistor connection, ceramic heater connections, bi-metal
connections, and re-install controller bracket. (FIGURE 3)
32.Connect fan harness, thermal fuse harnesses (upper and lower see FIGURES 2 & 3), igniter harness, and burner
sensor harness. Rotate gas pipe to the left back toward connection and secure using 1 screw (which should still be
in receptacle from before). (External units will have an additional freeze protection thermistor) (FIGURE 2)
33.Connect solenoid valve harnesses (SV1, SV2, SV3), flame rod wire (Yellow), electrode wire (black). (FIGURE 1)
34.Turn on water supply and gas supply checking for leaks.
35.Turn on 120 V power supply.
36.Install front panel and secure with 4 screws.
37.Test fire unit.
Condensing Water Heater Service Manual 48
RU80i/e, RU98i/e
100000354