Navien CH-180, Service Manual, Page: 39 / 155

37
4.6.5. Thermistor
Navien Part No.
Function
Check Point
BH1403081A(Black)
BH1403082A(Blue)
BH1403083A(Red)
BH1403084A(Yellow)
B
Failure Event
Effects
Error Code
E007, E008, E021, E022, E032, E033, E041, E042
Diagnostic
Color /
Number of wires
Measure cold, mixing, H/E, hot water temperature in the boiler.
Unable to properly measure water temperature within the boiler.
1. Visual inspection: Connection and/or breakage of wires.
2. Voltage check: Check range of voltage shown below.
3. Resistance check of sensor
1. Black – Black : DC 0 ~ 5 V
2. Blue – Blue : DC 0 ~ 5 V
3. Red – Red : DC 0 ~ 5 V
4. Yellow – Yellow : DC 0 ~ 5 V
5. Resistance-Open=infinite; Shorted=0 Nomal =4.121
̬
at 113
ı
1. If the Thermistors fail open or short, error code appears before starting
operation.
2. If resistance values are just off, the boiler will have temperature
fluctua tions in hot water.
G
Wire Color
: Black Wire Color
: Blue
Wire Color
: Red
Wire Colo
: Yellow
© Navien Ameri c a I n c . 20 1 0 CH series servi c e Manua l Version 1 .0