U-Line Outdoor Nugget Ice Maker Code 12: Water Too Low
A bare 12 on an Outdoor Collection nugget ice maker from U-Line means the water level is low. Too little water reaches the reservoir, so ice production slows or stops.
What does U-Line outdoor refrigeration code 12 mean?
When a UONB115 or UONP115 from the U-Line Outdoor Collection lights up a bare 12, the water level has dropped too low. The reservoir is not receiving enough water for the machine to carry on making nugget ice, and no letter sits in front of the number. Ice output slows or halts, and 12 stays on until water comes back.
12 at a glance
- Code
- 12
- Appliance
- U-Line outdoor refrigeration
- Applies to
- U-Line Outdoor Collection nugget ice makers
- Type
- Needs attention soon
- Can you clear it yourself?
- Sometimes, after the safe checks below
- Most likely cause
- Less water than normal is reaching the reservoir
What you may notice with 12
- The number 12 appears alone on the display
- Ice production slows down or stops
- Little or no water refills the reservoir
- The water line outside may look kinked or loose
How the outdoor refrigeration detects 12
A nugget ice maker needs a steady flow of water to make ice. Water runs into a reservoir, and the control keeps an eye on the level there. It expects the reservoir to hold enough water for the ice-making part of the cycle at each stage. When the level falls under what the control wants, it treats the situation as a water supply problem.
The control then shows 12 on the panel, with no letter ahead of it. Ice making slows or stops, because running with too little water would strain the parts that form the ice. The message stays until water returns to the reservoir. On an outdoor installation the supply line is often exposed, so a kink, a closed valve, a freeze or a loose fitting can cut the flow before any water reaches the machine.
Likely causes of 12
- Less water than normal is reaching the reservoir
- The shutoff valve or the line feeding the unit is restricted
- The level reading stays low although the reservoir is not empty
Can you keep using the outdoor refrigeration with 12?
Do not let the machine run for long with 12 on, because it is trying to make ice with too little water, and that strains the parts that form it. Switch it off while you check the shutoff valve and the supply line. If the line looks fine and 12 comes back, leave the unit off and have it looked at. The number alone is no danger to you, but protecting the ice-making parts is worth the wait.
What you can safely check
- First turn the unit off and take its power away at the plug or the breaker.
- Turn the water shutoff valve fully open.
- Walk the supply line outdoors and look for a kink, a frozen stretch or a loose fitting.
- Confirm that water runs at a nearby tap.
- Switch the unit on again after a minute.
- If 12 persists, contact us.
What our technician does for 12
- Check the water supply pressure and the inlet valve
- Test the level reading against the actual reservoir level
- Inspect the supply line for restrictions
How to keep 12 from coming back
- Keep the water shutoff valve fully open and avoid bumping it when working near the unit.
- Route the supply line so it cannot kink, and check the fittings after storms or heavy winds.
- Insulate or shield the exposed supply line wherever a freeze is possible.
Technical reference
- Code
- 12
- Appliance
- U-Line outdoor refrigeration
- Control family
- U-Line Outdoor Collection nugget ice makers
- 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.
Related U-Line outdoor refrigeration error codes
12 questions
What does 12 mean on an outdoor nugget ice maker?
It signals low water. Too little reaches the reservoir for nugget ice to keep forming, and the panel holds 12 until the level climbs back.
Is the supply line worth a look?
Yes. Outside, the hose crosses open ground where a kink or a pinch can be seen easily. Check it, and arrange a repair if 12 stays lit.
How does 12 differ from E13?
The number 12 is a water supply reading. E13 is an auger reading, which concerns the part that moves the ice, not the water level.
Does 12 clear by itself?
Yes, if water returns to the reservoir, for example after you open a valve or straighten a kinked line. If the supply is fine and 12 stays on, the level reading or the inlet needs a test.
Can a shut valve really cause 12?
It can. A valve that is partly closed, or a line that is pinched, lets too little water through, and the control reads that as a low level. Opening the valve fully is a safe first step.
Need help with 12?
A technician finds the cause at your bar or lanai and puts the price in writing before any part comes out.