Viking Undercounter Ice Machine Code 4 Flashes: bin and evaporator sensors both reported

What 4 Flashes means

On Viking Professional and Designer 15-inch undercounter ice machines in the VUIM, DUIM and DFIM 150 series, including the VUIM150T and DUIM150D, four flashes of the diagnostic LED mean both the bin sensor and the evaporator sensor are open or shorted. With both readings lost, the control cannot decide when to freeze, harvest or stop, and the machine usually does not make ice.

Common causes of 4 Flashes

Both sensors open or shorted
Shared connector or wiring problem
Control not reading its sensors

✓ One safe check you can try

1. Check that the bin is seated and the ice machine is plugged in. 2. Switch it off at the breaker for a few minutes, then restore power. 3. Count the LED blinks after the restart. 4. If four flashes return, shut the machine off and call us. A shared connector or wiring problem is possible, and that needs a technician to trace.

! Why to stop there

Two sensors failing together suggests a shared cause
Tracing it needs panel removal and a meter
We tell you the price in writing before we start, with a 30-day warranty

Opening a panel yourself does not automatically cancel a manufacturer warranty, but it can cause accidental damage, and some manufacturers set their own service conditions. Check your warranty terms, or ask us, before deciding.

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Other Ice Machine codes

2 FlashesViking Undercounter Ice Machine Code 2 Flashes: bin sensor open or shorted 3 FlashesViking Undercounter Ice Machine Code 3 Flashes: evaporator sensor open or shorted Check Water light (flashing blue)Viking Ice Machine Check Water Light Flashing Blue: No Water Supply CL (alternating with ICE)Viking Clear-Ice Machine Display CL and ICE: Time for a Cleaning Diagnostic LED: 2+3 blinksViking Beverage Center Ice Maker LED 2 Blinks, Pause, 3 Blinks: Both Thermistors Out of Range Diagnostic LED: 2 blinksViking Beverage Center Ice Maker LED 2 Blinks: Defrost Thermistor Reading Is Off Diagnostic LED: 3 blinksViking Beverage Center Ice Maker LED 3 Blinks: The Evaporator Thermistor Reads Wrongly Diagnostic LED: 4 blinksViking Beverage Center Ice Maker LED 4 Blinks: Potentiometer Signal Is Out of Range

4 Flashes4 Flashes questions

Why would both sensors fail at once?

It can be a shared connector or wiring problem, or a control reading both inputs wrongly. That is why we test the connection before replacing sensors.

How is 4 different from 2 and 3?

Two blinks name the bin sensor, three name the evaporator sensor, and four mean both are reported. We use the number to bring the right parts.

Should I turn the machine off?

Yes, it is best to turn it off until it is checked, because without its sensors it cannot control freezing or know when the bin is full.