mypros+
Error code reference

U-Line Ice Maker Error Code Evap T Open

Evaporator thermistor circuit is open.

U-Line codesU-Line ice maker codes

Evaporator thermistor circuit is open.

First step from the service manual

Inspect evaporator thermistor connection. Replace if necessary.

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 Evap T Open.

  • 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 Evap T Open means on a U-Line ice maker

The "Evap T Open" error code on a U-Line ice maker indicates that the evaporator thermistor circuit is reading as open, meaning the control board is receiving no signal from the thermistor sensor. The evaporator thermistor is a temperature-sensing component mounted on or near the evaporator coil. It feeds real-time temperature data to the control board so the ice-making cycle can be properly timed and regulated. When the circuit is open, the board has lost continuity with the sensor entirely, which prevents accurate monitoring of the evaporator's freeze cycle.

An open circuit in this context typically means one of three things: the thermistor itself has failed internally, the wiring harness connecting the thermistor to the control board has a break or disconnection, or the connector at either end of that harness has come loose or corroded. Unlike a short circuit, an open circuit means resistance is effectively infinite, and no usable signal can pass through. The control board interprets this as a fault condition and stops normal operation to protect the system.

The first diagnostic step is to inspect the evaporator thermistor connection physically. Check the connector at the thermistor and at the board for looseness, corrosion, or damage. If the connection looks intact, the thermistor itself should be tested for continuity and proper resistance. A failed thermistor will require replacement to restore normal ice maker operation.

Source: manufacturer service documentation.

Common causes of Evap T Open

  1. 01

    Loose or disconnected thermistor connector

    Wiring / connection

    The wiring connector at the evaporator thermistor or at the control board may have worked loose over time. Inspect both ends of the harness for secure seating and reattach any loose connector.

  2. 02

    Failed evaporator thermistor

    Part replacement

    The thermistor itself may have failed internally, resulting in an open circuit with infinite resistance. Testing the component with a multimeter for continuity will confirm whether it needs replacement.

  3. 03

    Damaged wiring harness

    Part replacement

    The wire between the thermistor and the control board may have a break, nick, or pinch point causing an open circuit. Visually trace the full length of the harness and check for any physical damage.

  4. 04

    Corroded or oxidized connector terminals

    Wiring / connection

    Moisture inside the ice maker cabinet can cause corrosion on the thermistor connector pins, increasing resistance to the point of an open circuit. Inspect the terminals closely and clean or replace the connector as needed.

  5. 05

    Control board failure

    Part replacement

    In rare cases, the control board's thermistor input circuit may have failed, causing it to misread a functioning thermistor as open. This is typically diagnosed only after confirming the thermistor and wiring are both good.

See the test procedure for each cause

Frequently asked questions about Evap T Open

What does Evap T Open mean on a U-Line ice_maker?
Evap T Open means the evaporator thermistor circuit is reading as open, which indicates the control board has lost its signal from the temperature sensor on the evaporator coil. This prevents the unit from monitoring its freeze cycle correctly. The fault is typically caused by a loose connector, a broken wire, or a failed thermistor sensor.
Can I fix the Evap T Open error myself?
In many cases, yes. Start by unplugging the unit and locating the evaporator thermistor connector, then check that it is fully seated at both the sensor and the control board. If the connection is secure, you can test the thermistor with a multimeter for continuity. A confirmed open thermistor will need to be replaced, which is a manageable repair for someone comfortable working with appliance components.
Is it safe to keep using my ice maker when the Evap T Open error is showing?
It is not recommended. The unit cannot accurately track evaporator temperatures without a functioning thermistor, which means ice production will be unreliable or will stop entirely. Continuing to run the unit in this state could also stress other components in the refrigeration system.
Will resetting the ice maker clear the Evap T Open error?
A reset may temporarily clear the displayed error, but the code will return if the underlying problem with the thermistor circuit has not been resolved. The fault needs to be corrected physically, either by reseating the connector or replacing the thermistor, before the error will stay cleared.
How much does it cost to repair the Evap T Open error on a U-Line ice maker?
If only a loose connector is involved, there may be no parts cost at all. If the evaporator thermistor needs replacement, parts alone typically run in the range of $20 to $60, depending on the specific model. Adding professional labor for diagnosis and replacement can bring the total repair cost to roughly $100 to $250.

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