Navien CH-180, Service Manual, Page: 48 / 155

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4.6.14. DHW Flow Sensor
Navien Part No.
Function
Check Point AASS9EXFS002 D
Failure Event
1. Unable to detect or measure any water flow rate.
2. Water leakage from the water flow sensor.
Effects
Error Code
Diagnostic
Color /
Number of wires
1. Red- black : DC 5 V
2. White – black : DC 0.3 ~ 4.5 V
1. To sensing water flow and GPM (Gallons per minute) for steady hot
water temperature.
1. Ignition sequence does not start.
2. Stop operating once detecting water leakage.
1. Visual inspection: Connection and/or breakage of wires.
2. Voltage check: Check range of voltage shown below.
3. Open/drain and verify that impellor spins freely
© Navien Ameri c a I n c . 20 1 0 CH series servi c e Manua l Version 1 .0
Water Outlet
Water Outlet