mypros+
Error code reference

U-Line Ice Maker Error Code Temp Lo 6H+

Zone temperature is more than 10°F under set point for over 6 hours.

U-Line codesU-Line ice maker codes

Zone temperature is more than 10°F under set point for over 6 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 Temp Lo 6H+.

  • 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 Temp Lo 6H+ means on a U-Line ice maker

The Temp Lo 6H+ error code on a U-Line ice maker indicates that the zone temperature has dropped more than 10°F below the programmed set point and has remained in that condition for over six consecutive hours. This is a sustained low-temperature fault, meaning the unit is not simply experiencing a brief temperature swing but has been running colder than intended for an extended period. The control board monitors zone temperature continuously, and this threshold of six hours is designed to distinguish between normal operational fluctuations and a genuine system problem.

The most likely causes involve the refrigeration system or its control components. A compressor running in an uncontrolled state, a stuck relay, or a failed DC output driving the compressor or evaporator fan can cause the zone to overcool beyond the set point. If the compressor is not cycling off when it should, or if the evaporator fan is running continuously without proper coordination, the refrigerant system can drive temperatures far below the target.

Diagnosis should begin with a check of the compressor, evaporator fan motor, and the relays and DC outputs that control them. Technicians should verify that control board outputs are cycling correctly, that relays are not stuck in the closed position, and that the compressor is responding to on and off commands from the board. A compressor that runs continuously due to a stuck relay or shorted output will consistently produce this fault. Temperature sensor accuracy should also be confirmed, since a miscalibrated or failed sensor could report a falsely low temperature even when actual zone conditions are within range.

Source: manufacturer service documentation.

Common causes of Temp Lo 6H+

  1. 01

    Stuck or failed compressor relay

    Part replacement

    A relay stuck in the closed position keeps the compressor running continuously without cycling off, causing uncontrolled cooling. Check the relay for proper switching operation and verify the DC output signal from the control board is cycling correctly.

  2. 02

    Control board DC output failure

    Part replacement

    A shorted or malfunctioning DC output on the control board can hold the compressor or fan motor in a constant-on state. Measure the output signal under operating conditions to confirm it is cycling as expected.

  3. 03

    Evaporator fan motor running continuously

    Part replacement

    If the evaporator fan runs without interruption due to a failed motor control circuit or stuck relay, airflow over the evaporator stays constant and drives zone temperatures below the set point. Inspect the fan relay and verify the motor responds to control signals.

  4. 04

    Temperature sensor fault

    Part replacement

    A failed or out-of-calibration temperature sensor may report a zone temperature that is lower than actual conditions, triggering this fault even when refrigeration operation is normal. Cross-check the sensor reading against an independent thermometer placed in the zone.

  5. 05

    Ambient temperature extremes

    Wiring / connection

    If the unit is installed in an unusually cold environment, the zone temperature may genuinely fall below set point without any component failure. Verify installation conditions are within the rated ambient temperature range for the unit.

See the test procedure for each cause

Frequently asked questions about Temp Lo 6H+

What does Temp Lo 6H+ mean on a U-Line ice_maker?
The Temp Lo 6H+ code means the ice maker zone temperature has been more than 10°F below the programmed set point for over six consecutive hours. It is a sustained low-temperature fault that indicates the refrigeration system is cooling beyond its target range for an extended period. This is typically caused by a compressor or evaporator fan that is not cycling off properly, often due to a stuck relay or failed control board output.
Can I fix the Temp Lo 6H+ error myself, or do I need a technician?
Some basic checks, like confirming proper installation conditions and ambient temperature, can be done without special tools. However, diagnosing compressor relay operation, DC output signals from the control board, and temperature sensor accuracy requires electrical testing equipment and familiarity with refrigeration control systems. Most repairs identified by this fault will require a qualified technician.
Is it safe to keep using my U-Line ice maker while this error is active?
Continued operation with this fault active is not recommended. The unit is running significantly colder than intended, which can affect ice quality, cause components to operate outside their designed parameters, and potentially lead to additional failures if the root cause is a stuck relay or runaway compressor. The unit should be inspected promptly.
Will resetting the unit clear the Temp Lo 6H+ error?
A reset may temporarily clear the displayed code, but if the underlying cause is not corrected, the fault will return once the six-hour threshold is met again. Resetting without repairing the faulty relay, control board output, or sensor does not resolve the problem. Always address the root cause before relying on a reset.
How much does it cost to repair a U-Line ice maker showing the Temp Lo 6H+ error?
Repair costs vary depending on the failed component. Relay replacements are generally the least expensive fix, typically in the range of $50 to $150 for parts and labor. Control board replacement can range from $200 to $500 or more depending on the board and labor rates. Temperature sensor replacement usually falls in the lower to mid range. Getting a diagnostic service call first will help identify the exact component before committing to a repair cost.

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