305E, 305I, 505E, 505I - A.O. Smith GTS-305-NE Service Manual

Component Replacement Instructions
Water Flow Control Assembly
7. Pull out the water flow servo assembly and disconnect the cable harnesses. (Figure 19)
A.water flow sensor harness (black/yellow/red wires)
B.water flow servo harness (red/blue/brown/yellow/gray or red/blue/brown/orange/yellow/gray wires)
C.heating element
heating element
connector
Assemble
8. Place the new water flow assembly inside the water heater and attach the cable harnesses.
9. Replace the O-ring on the water inlet (included in kit). Attach the water flow assembly through the
bottom of the compartment to the water inlet using 4 screws. The 2 shorter screws can be installed
first to connect the water flow assembly to the bottom of the compartment. Then install the 2 longer
screws through the water inlet.
10. Replace the O-ring on the water line (included in kit). Attach the water line to the water flow
assembly with 1 screw and bracket.
11. Install the front panel using 4 screws.
12. Turn on the water supply, power supply, and gas supply.
13. Open a hot water tap and ensure there are no leaks at the water heater.
On-Demand Gas Tankless Water Heater Service Manual

305e, 305i, 505e, 505i

100/101 and 200/201 Series
31
water flow servo connector
Figure 19
water flow sensor
connector