Navien CH-180, Service Manual, Page: 98 / 155

96
Error occurrence conditions and check items
5.20. 22Error
Error Description
If an error (short-circuit: 248 ı or higher) in the cold water inlet thermistor is
detected continuously for 3 seconds, the system displays the 22E error message
on the remote controller. The boiler maintains the Safety-Shutdown status.
1. Check if the cold water inlet thermistor connector is wet due to any reason,
including leakage.
2. Replace the defected cold water inlet thermistor.
3. Replace the PCB.
22E
Shortcircuit
of cold
water inlet
thermistor
Check
items
Is the inlet thermistor
normal?
Yes
No Replace Return thermistor
Resistance between two blue wires of CN 13 is from 0.8 to 20 KO
at normal condition.
Check connector
Caution : Before measuring resistance of the thermistor,
remove the connector form the PCB.
© Navien Ameri c a I n c . 20 1 0 CH series servi c e Manua l Version 1 .0