Navien CH-180 Service manual - page 75

73

Error conditions and Symptoms Analysis

5.8.07Error

Check method

Error

Description

Check the hot water temperature sensor. If a problem (open: 14

ı or lower) is 

detected for 3 seconds, the system displays the error message 07E on the indoor 

thermostat.

07E

Hot Water 

Outlet 

thermistor 

open Error

Check 

items

1. Check if the hot water temperature sensor is open and if the connector is 

    connected properly.

2. Replace the defective hot water temperature sensor.

3. Replace the PCB

Fault

Possible 

Causes

Check method

Check if the heating temperature sensor is open and if the 

connector is connected properly. 

Sensor 

error

Defective 

temperature 

sensor 

connector

Temperature 

sensor

Defective 

PCB

Other 

trouble

If the trouble continues despite the checking of above items, 

replace the PCB.

1. Measure the resistance of the temperature sensor.

2. If the resistance is abnormal, replace the temperature sensor.

Is the Supply thermistor

normal ?

Yes

No

Check connector

Replace Supply thermistor 

Resistance between two white 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.

©Navien America Inc. 2010

CH  series service Manual

Version 1.0