Service manual

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.