Component Replacement Instructions
11. Remove the 4 screws attaching the water inlet to the
underneath side of the water heater.
a. water flow sensor harness (black/yellow/red wires)
b. bypass servo assembly harness (white/red/yellow/orange/brown wires)
c. water flow servo harness (red/blue/brown/yellow/gray or red/blue/brown/orange/yellow/gray wires)
d. heating
element
12. Disconnect the cable harnesses (Figure 23):
Assemble
13. Pull out the water flow servo assembly and bypass servo assembly.
14. Remove 2 screws in order to separate the bypass servo assembly
from the water flow servo assembly. (Figure 24)
15. Replace the O-ring (included in kit) between the water flow servo assembly and the bypass servo assembly.
Attach the new water flow servo assembly to the bypass servo assembly with 2 screws.
16. Place inside the water heater and attach the cable harnesses.
17. Replace the O-ring on the water inlet (included in kit). Attach the water flow assembly 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.
18. Replace the O-ring on the water lines (included in kit). Attach the two water lines to the bypass servo
assembly with 1 screw each.
19. 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.
20. On indoor models, push the ducting over the fan assembly inlet and secure with the metal pinch clamp.
21. Attach the wire harness to the fan assembly (white, yellow, black, red wires).
22. Install the front panel using 4 screws.
23. Turn on the water supply, power supply, and gas supply.
24. Open a hot water tap and ensure there are no leaks at the water heater.
Figure 24
Water inlet
Figure 22
water flow servo
connector
heating element
connector
water flow sensor
connector
water flow servo
connector
Figure 23
Water Flow Control Assembly
On-Demand Gas Tankless Water Heater Service Manual
33
505e, 505i
100/101 and 200/201 Series