F4 on a Viking DFUD: the fill did not register enough flow pulses. Confirm the tap is open.
Model compatibility: Viking reuses codes across series and model years, so F4 / L4 may mean something different on another appliance or generation. Confirm this against your model’s documentation and record your full model number before acting.
Plain language
What this code means
F4 is a water intake fault, with fewer than 80 pulses in 60 seconds or the right count not reached within 255 seconds, and it interrupts the program.
F4 (L4 on LED models) is the water intake fault in the Viking DFUD service manual. Instead of a vague “not filling” condition, Viking defines it by numbers: as water comes in, the flow sensor sends pulses to the control while water enters, and at least 80 of them are expected inside 60 seconds.
The limits
At least 80 pulses must arrive within 60 seconds, so a slow trickle trips the fault.
The correct total pulse count must be reached within 255 seconds, so a fill that drags on without finishing trips it too.
Missing either limit interrupts the program, and it does not carry on past the failure.
Owner action in the manual
The owner table in the manual has a single action under water inlet fault: make sure the tap is open. Other things that limit the supply to the machine give the same low count, so they deserve a look too. Once the supply is confirmed, the manual’s way to take the indication off the display is to switch the main switch off and then on.
What a technician checks
Water supply
Flow sensor
Inlet valve
Wiring
Since the flow sensor does the counting, a perfectly normal fill may still raise F4 when the sensor misreports. Sorting the water-supply side from the counting side is the work.
Neighbouring fill codes
F5 is the reverse case, pulses counted while the valve is meant to be shut.
2-2 is the fill error on newer models, judged by pressure instead of pulses.
Viking dishwasher repair in Los Angeles
If the tap is open and F4 returns, call (310) 692-1112 for Viking dishwasher repair in Los Angeles. Tell them the tap was open and the power had been switched off and on. See the dishwasher repair page too.
Important safety warning. Do not attempt repairs involving electrical components, gas, water lines, refrigerant or sealed systems. Unplug the appliance if it is safe to reach the outlet, and leave internal diagnostics to a qualified technician.
Seeing this code on your Viking appliance?
Book a specialist visit for a clear estimate and approval before any repair.
