U-Line Nugget Ice Machine Code 12 (E12): Reservoir Level Too Low

E12 at a glance

Code

E12

Appliance

U-Line ice machine

Applies to

U-Line nugget ice machines: UONB115 and UHNB315

Type

Needs attention soon

Can you clear it yourself?

Sometimes, after the safe checks below

Most likely cause

The supply valve is shut or only partly open

What you may notice with E12

• Only the number 12 is shown, with no letter before it.
• Ice making has slowed or stopped.
• The reservoir looks low on water.
• The machine stays powered but produces little.

How the ice machine detects E12

Nugget ice is built from water held in a reservoir, so the machine needs that reservoir to stay supplied. The control follows the water level, and it expects the level to stay within a working band while ice is made and the supply refills what is used.

If the level sits below that band, the control cannot continue as normal. It slows or stops ice making and shows 12 until water returns. Most often the cause lies upstream, in a supply valve that is shut or part open, in a kinked fill line, or in a clogged inlet. The level sensing itself can also read low even when the reservoir holds some water. Once enough water arrives and the level recovers, the display clears and ice making resumes. The related high-water reading on these machines is 11.

Likely causes of E12

• The supply valve is shut or only partly open
• The fill line has a kink, or the inlet has clogged
• The level sensing reports low while some water is in the reservoir

Can you keep using the ice machine with E12?

You can leave it plugged in, but expect little or no ice while 12 shows. Running a machine low on water for long is not good for it, so do not leave it like that for days. Open the valve fully and check the line. If 12 stays on after that, turn the machine off and have the water path tested.

What you can safely check

1. Switch the machine off before you reach for the valve or the line.
2. Turn the supply valve to its fully open position.
3. Follow the water line and look for kinks.
4. Leave the machine off for ten minutes, then restart it.
5. Do not open panels.
6. If 12 appears again, contact us for testing.

What our technician does for E12

• Check flow at the supply valve and the fill line
• Clear or replace a clogged inlet
• Test the level sensing against the real water level
• Confirm the reservoir fills and 12 clears

How to keep E12 from coming back

• Keep the supply valve fully open and avoid bumping it when you clean nearby.
• Check the fill line for kinks after anyone moves the machine.
• If well water or hard water clogs the inlet, ask us about a filter and cleaning routine.

Technical reference

Code

E12

Appliance

U-Line ice machine

Control family

U-Line nugget ice machines: UONB115 and UHNB315

Maker documentation

U-Line owner manuals and support

Checked

November 2026

Code meanings come from the maker’s documentation and our own repair work; we do not reprint the maker’s document. Confirm the full model number before acting on a code. We are an independent repair company, not affiliated with U-Line Corporation.