22Error - Navien NP-180 Service Manual

5.13. 22Error

Error occurrence conditions and check items.
Error
If an error (short-circuit: 120
22E
Heat exchanger
sensor is detected, the system displays the 22E error message (cleared automatically)
input
on the remote controller and the PCB. The boiler maintains the Safety-Shutdown
temperature
sensor
status.
shortcircuit
1. Check if the heat exchanger input temperature sensor connector is wet due to
any reason, including leakage.
Check items
2. Replace the defected heat exchanger input temperature sensor.
3. Replace the PCB.
Is the hot water thermistor 1
normal?
Yes
Check connector
©Navien America Inc. 2010
Description
or higher) in the heat exchanger input temperature
No Replace hot water thermistor 1
Resistance between two red wires of CN 13 is from
0.8 to 20k ohm at normal condition.
Caution: Before measuring resistance of the thermistor,
remove the connector from the PCB.
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NR/NP series service Manual Version 2.0