Navien NCB-150E Service Manual page 108

Check method
Fault
Defective Dual Venturi
Dual Venturi action error
Possible Causes
1. Disconnect all cables from the Dual Venturi.
cable or harness
2. Using a multi-meter, test the Dual Venturi electrical wiring.
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
Dual Venturi not
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.
Troubleshooting 107