Lochinvar SNA285-125 Manuale Utente
63
12
Troubleshooting
(continued)
Table 12A Troubleshooting Chart - No Display
FAULT
CAUSE
CORRECTIVE ACTION
No Display
- No 120 VAC supplied to unit.
• Check external line switch, fuse, or breaker.
• Check wiring harness connection between display
board and main control board. Connect harness at both
points.
board and main control board. Connect harness at both
points.
- Bad display board.
• Replace board.
- Bad main control board.
• Replace the main control board.
- Blown fuse.
• Replace fuse F3 on the main control board, see
page 62 of this manual.
No Burner
Operation
- Tank temperature set point satisfied.
• Review temperature setting.
- Unit locked out on fault.
• Consult display for specific fault. Refer to fault
descriptions on page 66 of this manual for corrective
actions.
descriptions on page 66 of this manual for corrective
actions.
Unit Does
Not Modulate
Above 50%
- Flue sensor open.
• 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 12C on page 64 of this manual.
to Table 12C on page 64 of this manual.
Installation & Service Manual
TM