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Component Replacement Instructions
20. Remove 2 screws above the exhaust. Pull assembly from the unit. (Figure 42)
21. Install the largest O-ring (included in kit) over the water outlet tube and the two smaller O-rings
(included in kit) over the bypass servo tubes. (Figure 38)
22. Remove any other attached items and install on the new heat exchanger.
Connect Pressure Tube and Wire Harness Attachments
23. Install the new heat exchanger using 2 screws above the exhaust and 3 screws behind the fan.
(Figures 41, 42)
Install Burner and Burner Cover Plate (Figure 40)
24. Connect wire harness attachments.
25. Connect the pressure tube. Attach the ignition line connection with 1 screw.
Install Gas Manifold and Connect PC Board
26. Replace the combustion chamber packing (included in kit) removing
any residue from old packing. Insert the burner and place the burner
cover plate into position. Attach the burner cover plate first with 8
screws and then attach the burner with 2 screws.
27. Make sure that the two black packings (Figure 43) are intact on the
gas control assembly. Attach the gas manifold with 3 machine screws
at the gas control assembly. Replace the lower and upper packings
(included in kit) for the manifold plate removing any residue.
Connect Water Lines (Figure 38)
28. Attach the gas manifold with 6 screws at heat exchanger.
29. Attach the ignition line at the burner cover plate.
Install Fan Assembly (Figure 37)
30. Attach the PC Board to the heat exchanger with 1 screw.
31. Attach the water outlet line and bracket with 1 screw.
32. Attach the two lines to the bypass servo assembly with 1 screw and 1 bracket for each line.
33. Install the fan assembly by inserting the tab on the fan assembly into the slot at the base of the heat
exchanger and attaching with two screws.
34. Attach the wire harness to the solenoid on the gas manifold (brown, black wires).
35. Attach the wire harness to the fan assembly (white, yellow, black, red wires).
Figure 43
WARNING
Failure to correctly assemble the components according to these instructions
could result in a gas leak or explosion.
Installation
On-Demand Gas Tankless Water Heater Service Manual
40
Heat Exchanger
505e/o