Diagnosis
‘nF’ stands for ‘No Fill.’ The machine didn’t detect water entering the tub within the expected time at the start of a cycle.
How to Fix It
First, check the obvious: are both hot and cold water supply valves behind the washer fully open? Is the water inlet hose kinked? Next, check the inlet screens as described in the slow-fill problem (clogged screens are a top cause). Make sure you’re not using the ‘Clean Washer’ cycle for this test—some models won’t fill on that cycle without a specific button sequence.
If That Didn't Work
If water supply is good, the pressure switch (which tells the board the tub is filling) might be faulty or its tube might be clogged. Or, the water inlet valve itself could be electrically failed and not opening. These require a multimeter to test and are a job for a technician.
Heads Up
The ‘nF’ error will usually trigger an automatic beeping alarm. You’ll need to press the ‘Pause/Cancel’ button twice to clear the error code before you can try starting a new cycle after fixing the water issue.