Component Replacement Instructions
505i
Remove Burner and Burner Cover Plate (Figure 59)
16. Remove the 8 screws attaching the burner cover plate to the combustion chamber. Move the cover
plate to the side. It is not necessary to disconnect the wire harness from the burner cover plate.
17. Remove the 2 screws attaching the burner to the heat exchanger. Pull out the burner.
Disconnect Gas Line and Wire Harness Attachments
18. Disconnect the pressure tube from the heat exchanger and unscrew the ignition line connection.
(Figure 59)
19. Remove the wire harness attachments - sensors, heating elements, fusible link brackets. Ensure
that the small O-ring in the thermistor is removed. (Figure 60)
Pressure tube
Ignition line
connection
8 screws
(burner cover plate)
2 screws (burner)
Figure 59
Brackets for
fusible link
Sensors
Heating
elements
Figure 60
Thermistor
Heat Exchanger
On-Demand Gas Tankless Water Heater Service Manual
47
