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240 (T-H3J), 340 (T-H3S) and 540 (T-H3) models Service Manial
Ver. 1.00
CONFIDENTIAL
10-11. Bypass valve (540 (T-H3)
models only)
Part #
• 319143-464 (EKD58)
540 (T-H3) models only
Unit Part#
#403
Function
1. Mixes hot water from the heat exchanger with cold water from the water
inlet in order to modulate and control the water heater’s outlet water
temperature.
2. Keeps the water temperature in the heat exchanger stable, preventing
low-temperature corrosion by reducing condensation buildup in heat
exchanger.
Failure events
1. Water leakage from valve.
2. The valve cannot modulate properly.
Effects on the water heater
if bypass valve fails
1. Water leakage from failed valve can damage other water heater
components.
2. Temperature fluctuations in the hot water output.
Error codes when bypass
valve fails
N/A
Diagnostic
1. Visual inspection: connection/breakage of wires.
2. Check voltages and resistance: proper range of values shown below.
Color / Number of wires
Brwon - Red
3.0 to 11 VDC and 50 to 85 Ω
Checkpoint
J1
The physical appearance of the bypass valve is similar to that of the flow adjustment valve.
However, their functions differ and cannot be substituted for each other
>PS+SPS-GF<
2-1/2" (66 mm)
3-3/8" (84 mm)
1-7/8" (47 mm)
BYPASS
WATER IN
BYPASS
WATER OUT
Bypass
valve
BYPASS
WATER IN
BYPASS
WATER OUT