Navien NCB-180 Service Manual page 99

Check method
Fault Possible Causes
Defective Dual
Venturi cable or
Dual Venturi
action error
Dual Venturi not
96 NCB Service Manual
1. Disconnect all cables from the Dual Venturi.
2. Using a multi-meter, test the Dual Venturi electrical wiring.
harness
1. Turn off the power to the unit using the main power switch (do not use the front
panel power button) and wait for 10 seconds.
2. Turn on the power.
3. Wait until Fan Auto Adjusting is complete.
4. Enter the Dual Venturi Test Mode and perform a test.
1) Repeat the test at least twice. Turning the unit ON and OFF once makes one test
cycle. ON
operating
2) Confirm that the Dual Venturi is operating correctly.
a. Listen to the Dual Venturi while it is running and check for operational noise
(clicks at unit ON and unit OFF).
b. If operational noise cannot be heard because of ambient noise, disassemble
the Dual Venturi and perform a visual inspection.
5. If error message (E060) occurs, replace the Dual Venturi.
6. If a Dual Venturi error does not occur, replace the APS.
Check method
→ → → →
OFF ON OFF ...... is the minimum sequence.
Version 1.0