U-Line Refrigerator Error L Temp Lo 12H+: Left Side Overcooling
L Temp Lo 12H+ is the extended cold alert for the left zone: it has stayed roughly ten degrees F under the set point for over twelve hours.
What does U-Line refrigerator & drawers code L Temp Lo 12H+ mean?
L Temp Lo 12H+ is the extended overcooling alert for the left half of a U-Line refrigerator. The L is the left side. It shows when the left zone has stayed roughly ten degrees F under the set point for over twelve hours. That much time points past a simple swing. A changed left set point, a thermistor reading wrongly, or a control or damper problem may be keeping the left side colder than you asked for.
L Temp Lo 12H+ at a glance
- Code
- L Temp Lo 12H+
- Appliance
- U-Line refrigerator & drawers
- Applies to
- U-Line digital control, left temperature zone
- Type
- Low urgency
- Can you clear it yourself?
- Sometimes, after the safe checks below
- Most likely cause
- A left set point that was changed and never put back
What you may notice with L Temp Lo 12H+
- L Temp Lo 12H+ is displayed on the control
- Left side items have partly frozen overnight
- Ice builds on left shelves or containers
- The left stays cold even after you change the set point
How the refrigerator & drawers detects L Temp Lo 12H+
The control expects the left zone to hover near its set point as cooling cycles. If the left side falls and stays far below target, it starts a timer, and once that cold period is past 12 hours the message becomes L Temp Lo 12H+.
The trigger gap is roughly ten degrees F below the set point. Overcooling that lasts half a day tells the control its left-side cycling is not behaving. It cannot see the reason. A mistaken set point, a sensor that misreports, or a damper or control stuck open can each leave the left zone cold, so the sequence of checks matters more than guessing.
Likely causes of L Temp Lo 12H+
- A left set point that was changed and never put back
- A left zone thermistor whose reading does not match the true temperature
- A control or damper problem that keeps feeding cold air to the left
Can you keep using the refrigerator & drawers with L Temp Lo 12H+?
You may keep using the unit, because a cold zone is not a hazard. The cost is frozen produce, split bottles and extra energy use on the left. Measure with a thermometer, fix the left set point and store fragile items on the right. If the left still freezes after the setting is correct, turn it off and arrange service.
What you can safely check
- Switch the breaker off or unplug the refrigerator before changing shelves or clearing the left vent area.
- Look at the left set point on the control and return it to your preferred value if it changed.
- Confirm the left door closes properly and nothing presses against the vents.
- Compare a refrigerator thermometer in the left zone with the display over a few hours.
- If L Temp Lo 12H+ stays, call us.
What our technician does for L Temp Lo 12H+
- Check the left zone thermistor against a known reference
- Test the control's left cooling cycle for runaway operation
- Inspect and test the left damper and its drive
- Replace the part holding the left zone too cold
How to keep L Temp Lo 12H+ from coming back
- After adjusting the left set point, write it down so an accidental change is easy to spot.
- Do not stand tall bottles or boxes against the left vents, which can upset airflow and temperature.
Technical reference
- Code
- L Temp Lo 12H+
- Appliance
- U-Line refrigerator & drawers
- Control family
- U-Line digital control, left temperature zone
- 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 refrigerator & drawers error codes
L Temp Lo 12H+ questions
What does L Temp Lo 12H+ mean?
It means the left side has run roughly ten degrees F under the set point for over twelve hours. The control reports it because the left side is overcooling and not recovering.
Is L Temp Lo 12H+ the same as the shorter left cold alert?
It is the same condition as the shorter left cold alert, but it has lasted twice as long. That makes a simple setting mistake less likely and a sensor or damper problem more likely.
Can I keep food on the left side with L Temp Lo 12H+?
Yes, most items are fine, but watch for freezing on the left. Move produce, eggs and drinks to the right side so they do not freeze, and confirm the real temperature with a thermometer.
Does L Temp Lo 12H+ damage the refrigerator?
Overcooling is mostly a food and energy problem. Even so, a damper that stays open or cooling that never stops means a part is not doing its job, so it should be tested.
What should I mention when I call about L Temp Lo 12H+?
Give us the code text, the left set point you want, what a thermometer reads and whether left items are freezing. Mention whether anyone changed the left set point lately, because that narrows the cause.
Need help with L Temp Lo 12H+?
A technician finds the cause at your bar or lanai and puts the price in writing before any part comes out.