Heat Exchanger (Ru80I/E/98I/E) - Rinnai REU-KA2530FFUD-US Service Manual

KB Series Component Replacement Instructions
Heat Exchanger
1.Turn off gas supply.
2.Turn off 120 V power supply.
3.Turn off water supply and drain unit.
4.Remove four screws securing front panel. Remove front panel.
5.Disconnect solenoid valve harnesses (SV1, SV2, SV3), flame rod wire (yellow), electrode wire (black). (FIGURE 1)
6.Disconnect fan harness, thermal fuse harnesses (upper & lower FIGURES 2 & 3), igniter harness, & burner sensor
harness. Remove 1 screw from gas pipe to manifold connection and rotate gas pipe to the right to move it out of the
way. (Put screw back into connection so as not to lose it) (External Units will have a freeze protection thermistor)
(FIGURE 2)
7.Disconnect thermal fuse harness, heat exchanger thermistor connection, ceramic heaters, bi-metal connectors, &
remove controller bracket. (FIGURE 3)
Solenoid Harnesses
Flame Rod Wire
Thermal Fuse Harness
FIGURE 3
Thermistor Connection
Ceramic Heaters
Bi-Metal
Connectors
Condensing Water Heater Service Manual
Electrode Wire
FIGURE 1
Bracket
Screw
Burner Sensor Wire
Thermal Fuse Harness
43
RU80i/e, RU98i/e
Fan Harness
Igniter Harness
FIGURE 2
100000354