mypros+
Error code reference

U-Line Ice Maker Error Code R Temp Hi 12H+

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

U-Line codesU-Line ice maker codes

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

First step from the service manual

Check compressor, evaporator fan and related relays and DC outputs.

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

MyPros+ Max

Get the full diagnostic procedure for R Temp Hi 12H+.

  • Step-by-step tests with expected resistance, voltage, and continuity values
  • Wiring diagram references and connector pinouts from the OEM service manual
  • Verified part numbers when replacement is required
Get the full procedure

$29/month · Cancel anytime · Or $9.95 3-day pass

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

The R Temp Hi 12H+ error code on a U-Line ice maker indicates that the right zone temperature has remained at least 10 degrees Fahrenheit above the programmed set point for a continuous period exceeding 12 hours. This is a sustained thermal fault, meaning the unit has been unable to maintain proper cooling in the right zone for an extended duration. The 12-hour threshold distinguishes this from brief or recoverable temperature swings, signaling a persistent mechanical or electrical failure rather than a temporary door-open event or heavy load condition.

The right zone cooling system relies on the compressor to circulate refrigerant, the evaporator fan to move conditioned air across the evaporator coil, and the associated relays and DC control outputs that command these components. If any of these elements fails or operates outside normal parameters, the zone will gradually warm and eventually trigger this code. A failed compressor will produce no refrigeration at all, while a seized or non-functioning evaporator fan will prevent cold air from circulating even if the refrigerant system is operating correctly.

Diagnostic priority should be placed on verifying compressor operation, checking whether the evaporator fan is spinning at the correct speed, and testing the relays and DC outputs that control these components. Relay failures can cause intermittent or complete loss of compressor or fan activation. DC output faults at the control board level may prevent command signals from reaching the load components entirely. A technician should check for proper voltage at each component and confirm that control board outputs are functioning before condemning any single part.

Source: manufacturer service documentation.

Common causes of R Temp Hi 12H+

  1. 01

    Evaporator fan failure

    Part replacement

    If the evaporator fan motor has seized or stopped running, cold air cannot circulate through the right zone even if the compressor is working. Listen for fan operation and check for proper voltage at the fan motor terminals.

  2. 02

    Compressor not running

    Part replacement

    A failed or overloaded compressor will result in a complete loss of refrigeration to the zone. Check for voltage at the compressor terminals and verify the compressor is not tripping on its overload protector.

  3. 03

    Relay failure

    Part replacement

    Relays controlling the compressor or evaporator fan can fail in the open position, cutting power to the component they control. Testing relay continuity and switching function will confirm whether a relay is at fault.

  4. 04

    DC output fault at the control board

    Part replacement

    The control board supplies DC output signals to drive the compressor relay and fan motor. If the board is not producing the correct output voltage, the cooling components will not receive a run command regardless of their own condition.

  5. 05

    Restricted airflow or dirty condenser

    Wiring / connection

    Blocked ventilation around the unit or a heavily soiled condenser coil can reduce cooling efficiency enough to cause sustained zone temperature rise over many hours. Inspect condenser coils and verify the installation has adequate clearance.

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 ice maker?
This error means the right zone of your U-Line ice maker has been running 10 or more degrees above its set point temperature for over 12 consecutive hours. It indicates a sustained cooling failure rather than a brief temperature spike. The most common causes involve the compressor, the evaporator fan, or the relays and control board outputs that operate those components.
Can I fix the R Temp Hi 12H+ error myself?
Some basic checks are within reach of a knowledgeable DIYer, such as inspecting for blocked vents, cleaning the condenser coil, and confirming the unit has adequate clearance for airflow. However, diagnosing compressor operation, testing relay continuity, and measuring DC control board outputs require electrical testing equipment and a working knowledge of appliance circuits. If those components are involved, a qualified appliance technician is recommended.
Will resetting the unit clear the R Temp Hi 12H+ error?
A reset may temporarily clear the error code from the display, but it will not resolve the underlying problem. If the compressor, evaporator fan, or related relay is not functioning correctly, the zone temperature will rise again and the code will return. The fault must be identified and repaired for the error to be permanently cleared.
Is it safe to continue using my U-Line ice maker when the R Temp Hi 12H+ error is active?
You should stop relying on the ice maker for ice production while this error is active, as the right zone is not maintaining safe temperatures. Ice quality and yield will be compromised, and continued operation without repair could place additional strain on components like the compressor. It is best to address the fault promptly and avoid consuming ice produced during the fault period.
How much does it cost to repair the R Temp Hi 12H+ error on a U-Line ice maker?
Repair costs vary depending on which component has failed. Evaporator fan motor replacements typically fall in the range of $100 to $250 including parts and labor. Relay replacements are generally less expensive, often $75 to $175. Compressor replacement is the most costly repair, commonly ranging from $400 to $800 or more depending on the model and labor rates in your area. A diagnostic service call to identify the faulty component is usually required first.

Related U-Line ice maker codes

All U-Line ice maker codes
View all 61 U-Line ice maker codes

78,000+ service manuals · 160,000+ error codes · 55+ brands

Get Started

$29/month · Cancel anytime · Or $9.95 3-day pass