Lochinvar Shield SWR125 Installation & Service Manual page 77

12
Troubleshooting
Table 12F (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Water Heater
Interface
FAULT
LOW VOLTAGE
NO FLUE TEMP
CHANGE
SENSOR FAULT
LOCKOUT INLET
SENSOR FAULT
OUTDOOR
SENSOR MISSING
(continued)
DESCRIPTION
120 vac input to the main control board has
dropped below 80 vac.
The flue temperature did not change after
the burner started firing.
DHW sensor is not connected.
The inlet sensor has been disconnected.
The inlet sensor has been shorted.
The outdoor sensor has opened or shorted.
Installation & Service Manual
CORRECTIVE ACTION
• Check 120 vac supply to the transformer.
• Check wiring connections at the low voltage
terminal strip.
• Check the wire size/length to remote devices.
• Replace the transformer.
• Check 24V.
• Verify that the flue sensor is installed.
• Check the sensor and its associated wiring. Repair or
replace the sensor or wiring if damaged.
• Check the DHW sensor and its associated wiring.
Repair or replace as needed.
• Check the sensors and their associated wiring.
Repair or replace the sensor or wiring if damaged.
• Measure the resistance of the sensors and compare
the resistance to the tables on page 70 of this
manual.
• Replace the sensor if necessary.
• Check the sensors and their associated wiring.
Repair or replace the sensor or wiring if damaged.
• Measure the resistance of the sensors and compare
the resistance to the tables on page 70 of this
manual.
• Replace the sensor if necessary.
• Check the sensors and their associated wiring.
Repair or replace the sensor or wiring if damaged.
• Measure the resistance of the sensors and compare
the resistance to the tables on page 70 of this
manual.
• Replace the sensor if necessary.
77