Navien CH-180 Service manual - page 98

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 20KO 

at normal condition. 

Check connector

Caution: Before measuring resistance of the thermistor,

                remove the connector form the PCB.

©Navien America Inc. 2010

CH  series service Manual

Version 1.0