78
Installation & Service Manual
13
Troubleshooting
Table 13-4 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface
ERROR CODE
DESCRIPTION
CORRECTIVE ACTION
b06
120 vac input to the main control board has
dropped below 80 vac.
• 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.
n01
The flue temperature did not change after
the burner started firing.
• Verify that the flue sensor is installed.
• Check the sensor and its associated wiring. Repair or
replace the sensor or wiring if damaged.
n06
DHW sensor is not connected (combi only).
• Check the DHW sensor and its associated wiring.
Repair or replace as needed.
n07
The inlet sensor has been disconnected.
• 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 71 of this
manual.
• Replace the sensor if necessary.
n08
The inlet sensor has been shorted.
• 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 71 of this
manual.
• Replace the sensor if necessary.
n09
The outdoor sensor has opened or shorted.
• 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 71 of this
manual.
• Replace the sensor if necessary.
