Navien NHB-055 Service Manual page 102

Check method
Fault
Dual Venturi action error
102 NHB Service Manual
Possible Causes
1. Disconnect all cables from the Dual Venturi.
Defective 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
2. Turn on the power.
3. Wait until Fan Auto Adjusting is complete.
4. Enter the Dual Venturi Test Mode and perform a test.
Dual Venturi not
operating
5. If error message (E060) occurs, replace the Dual Venturi.
6. If a Dual Venturi error does not occur, replace the APS.
front panel power button) and wait for 10 seconds.
1) Repeat the test at least twice. Turning the unit ON and OFF once makes one
test cycle. ON → OFF → ON →
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.
Check method
OFF → ...... is the minimum sequence.
Version 1.0