Table 3A - Troubleshooting Chart - No Display - Lochinvar ArmorX2 1.3 Service Manual

3
Troubleshooting
Table 3A Troubleshooting Chart - No Display
FAULT
- No 120 VAC supplied to unit.
No Display
- No voltage through the switch.
- Bad display board.
- Bad main control board.
- Blown fuse.
- Main control board temperature set point
satisfied.
No Burner
- Remote thermostat satisfied.
Operation
- Unit locked out on fault.
- Water heater controlled by BMS.
- Flue sensor open.
Unit Does
Not Modulate
Above 50%
(continued)
CAUSE
Service Manual
CORRECTIVE ACTION
• Check external line switch, fuse, or breaker.
• Check position of ON/OFF switch. Turn switch to the
ON position.
• Check 120 VAC through the ON/OFF switch.
• Check wiring harness connection between display
board and main control
harness at both points.
• Replace switch.
• Replace board.
• Replace the main control board.
• Replace fuse F3 on the main control board, see
page 38 of this manual.
• Review temperature setting.
• Review remote thermostat setting.
• Consult display for specific fault.
descriptions on page 42 of this manual for corrective
actions.
• Check BMS parameter settings.
• Verify that the flue sensor is located in the flue outlet.
• Check wiring connections at the flue sensor.
• Check the resistance of the flue sensor and compare
to Table 3C on page 40 of this manual.
board. Connect
Refer to fault
39