A.O. Smith GTS-305-NE Service Manual page 42

Component Replacement Instructions
Heat Exchanger
Remove Gas Manifold (Figure 46)
13. Remove the 6 screws that attach the gas manifold to the combustion chamber (part of the heat exchanger
assembly).
14. Remove the 3 screws that attach the gas manifold to the gas valve. These screws are machine screws and
must be used at these locations.
15. Pull out the ignition line and remove the gas manifold.
Remove Burner and Burner Cover Plate (Figure 47)
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.
18. Disconnect the pressure tube from the heat exchanger and unscrew the ignition line connection.
8 screws
(burner cover plate)
2 screws (burner)
On-Demand Gas Tankless Water Heater Service Manual
305i
Ignition line
6 screws (gas manifold)
PC Board screw
3 machine screws
(gas valve)
42
Figure 46
Figure 47
Pressure tube
Ignition line
connection