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Error code reference

U-Line Refrigerator Error Code R Temp Hi 12H+

Right Zone temperature is +10° over set point for over 12 hours.

U-Line codesU-Line refrigerator codes

Right Zone temperature is +10° over set point for over 12 hours.

First step from the service manual

If excessive frost is also noted, inspect door and door gasket for proper seal and alignment.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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What R Temp Hi 12H+ means on a U-Line refrigerator

The R Temp Hi 12H+ error code on a U-Line refrigerator indicates that the right zone temperature has been running at least 10 degrees Fahrenheit above the user-set target temperature for a continuous period exceeding 12 hours. This is a sustained thermal fault, not a momentary spike. The refrigerator's control board monitors zone temperatures against their set points, and this alert is only triggered after the deviation persists well beyond normal recovery windows. By the time this code appears, the right zone has been operating outside safe food storage ranges for an extended period.

The most immediate diagnostic focus, especially when excessive frost is also present, is the door and door gasket. A damaged, misaligned, or poorly sealing gasket allows warm, humid ambient air to enter the compartment continuously. This causes the compressor to work harder without achieving the target temperature, and the moisture introduced by the warm air will freeze on evaporator coils or interior surfaces, creating excessive frost buildup. A warped door, loose hinge, or compressed gasket material are all common contributors to this failure mode.

Beyond door seal issues, sustained high temperature in a single zone can also point to problems with the evaporator fan motor, a refrigerant charge issue, a blocked or frosted-over evaporator coil, or a faulty thermistor providing incorrect temperature readings to the control board. Diagnosing the root cause requires distinguishing between an actual temperature elevation and a sensor error, as well as checking airflow paths and refrigerant system performance.

Source: manufacturer service documentation.

Common causes of R Temp Hi 12H+

  1. 01

    Failed or misaligned door gasket

    Part replacement

    A worn, torn, or improperly seated door gasket allows warm air to continuously enter the right zone, preventing the unit from reaching and holding the set temperature. Look for visible gaps, frost buildup near the door perimeter, or a gasket that does not spring back when pressed.

  2. 02

    Door misalignment or hinge issue

    Wiring / connection

    If the door does not close squarely against the cabinet, even a good gasket will not seal properly. Check that the door hangs level and closes flush on all sides without requiring extra force.

  3. 03

    Frosted-over evaporator coil

    Wiring / connection

    Excessive frost accumulation on the evaporator coil restricts airflow and severely reduces cooling capacity in the affected zone. This often accompanies the door seal problem and may require a manual defrost cycle to confirm and resolve.

  4. 04

    Faulty right zone thermistor

    Part replacement

    A malfunctioning temperature sensor can report inaccurate readings to the control board, triggering the high temperature fault even if actual conditions are closer to normal. Resistance values should be tested against specifications for the right zone sensor.

  5. 05

    Evaporator fan motor failure

    Part replacement

    The evaporator fan circulates cooled air through the right zone compartment. If the fan motor has failed or is running intermittently, cold air will not distribute properly and zone temperature will rise steadily over time.

See the test procedure for each cause

Frequently asked questions about R Temp Hi 12H+

What does R Temp Hi 12H+ mean on a U-Line refrigerator?
This code means the right zone of your U-Line refrigerator has been at least 10 degrees above the set temperature for more than 12 continuous hours. It is a sustained cooling failure alert, not a brief fluctuation. The unit has been unable to maintain proper temperature in the right zone long enough to trigger a timed alarm. Immediate inspection of the door gasket and door alignment is the recommended first step.
How do I fix the R Temp Hi 12H+ error on my U-Line refrigerator?
Start by inspecting the right zone door and gasket for visible damage, gaps, or misalignment, especially if you also notice frost buildup inside the compartment. If the gasket seals properly and the door closes correctly, check whether the evaporator coil is heavily frosted, as this restricts airflow and cooling. For issues beyond the door seal, a technician may need to test the thermistor, evaporator fan motor, and refrigerant system.
Will resetting my U-Line refrigerator clear the R Temp Hi 12H+ error?
A reset may clear the displayed code temporarily, but the error will return if the underlying cause has not been fixed. Because the fault requires 12 or more hours of sustained high temperature to trigger, a reset without a repair only delays the alert while the cooling problem continues. Address the root cause first before relying on a reset.
Is my food safe after the R Temp Hi 12H+ error appears?
Food safety is a concern with this error, since the right zone has been above the safe temperature range for an extended period. Perishable items like meat, dairy, and prepared foods that have been held above 40 degrees Fahrenheit for more than two hours are generally considered unsafe. Review the contents of the right zone carefully and discard anything that may have been compromised.
How much does it cost to repair a U-Line refrigerator showing R Temp Hi 12H+?
Repair costs vary depending on the cause. Replacing a door gasket typically falls in the range of $50 to $150 for parts and labor, while a thermistor or evaporator fan motor replacement may run $100 to $300 or more depending on parts availability and local labor rates. If the issue involves the refrigerant system or control board, costs can be higher. A diagnostic service call will help identify the specific failed component before committing to a repair.

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