iN401 - iN501 Wiring Diagrams and Troubleshooting
56
May
2019
-
Revision
00
Description
Possible
Cause
Remedy
Flue
Temperature Exceeded Set Limit
• Incorrect vent set up.
• High inlet temperature.
• Faulty sensor wiring.
• Faulty sensor.
• Faulty controller.
• If vent pipe material is CPVC or polypropylene, ensure that
CPVC is selected in the vent material screen.
• Ensure inlet temperature is lower than 150°F if vent pipe
material is PVC or lower than 190°F if vent pipe material is
CPVC or polypropylene.
• Check for nicked or broken sensor wiring and connectors.
Also check for corroded or wet connectors.
• Measure resistance of sensor at connector (18 kΩ at 50°F,
10 kΩ at 77°F, 3 kΩ at 140°F).
• Replace controller
Blocked Flue Fault
• Exhaust blocked (bird, etc).
• Backed up condensate.
• Wiring loose (switch open).
• Check exhaust termination. Check exhaust connection at
water heater. Install screens to prevent blockage.
• Check slope of drain. Check for double loops, air locks, or
debris in loop.
• Check wiring.
Flue sensor
• Unplugged connectors.
• Faulty sensor wiring.
• Faulty sensor.
• Flue temperature sensor.
• Inlet water temperature sensor.
• Faulty controller.
• Check connectors and ensure they are securely connected
• Check for nicked or broken sensor wiring or connectors. Also
check for corroded or wet connectors
• Measure resistance of sensor at connector (18 kΩ at 50°F,
10 kΩ at 77°F, 3 kΩ at 140°F)
• Replace controller.
Cascading
Alert
• Loss of communication between
units.
• Check for broken or nicked communication cable or loose
connector.
• Ensure that the communication cable is not bundled or tied to
any high voltage lines.
• Ensure dip switch (SW3) is ON in first and last units and OFF
in all other units.
• Ensure each unit numbering is unique.
