A.O. Smith GTS-305-NE Service Manual page 32

Component Replacement Instructions
Water Flow Control Assembly
Due to design changes, the new valve may appear different than the installed valve in
NOTICE
color, size, and in the number of wires in the harness connections.
1. Turn off the gas supply.
2. Turn off the 120 V power supply.
3. Turn off the water supply. Drain all water from the appliance.
4. Remove four screws securing the front panel. Remove front panel.
Remove Fan Assembly (Figure 20)
5. Disconnect wire harness at the fan assembly. Disconnect the air temperature thermistor (two white wires) at
the connection with the white and orange wires within the wire bundle.
6. Pull out the harness attached to the solenoid on the manifold to make room to pull out the fan assembly.
7. Remove the 2 screws that attach the fan assembly to the bottom of the burner.
8. On indoor models, loosen the ducting from the fan assembly by pinching open the metal clamp.
9. Pull out the fan assembly.
2 screws
Ducting and
metal clamp
(indoor models
only)
Remove the water flow assembly (Figure 21)
10. Remove 2 screws and 2 brackets at the water
flow servo assembly. The brackets can be
left on the water lines. Pull out the water
lines.
On-Demand Gas Tankless Water Heater Service Manual
505e/o, 505i
100/101 and 200/201 Series
Water flow
servo assembly
connections
Figure 20
32
Solenoid on the manifold
Wire harness connection
on the fan assembly
Wire harness bundle
(connection to orange /
white wires)
Figure 21