E00AHT Cooling Systems

AHT Cooling Systems E00 Error Code

Fault in electronic expansion valve E01 Fault in suction pressure sensor E02 Fau

Source: vento-spi__aht-vento-iom.pdf

What does AHT Cooling Systems E00 mean?

The controller detects a fault in the electronic expansion valve (EEV). This valve regulates refrigerant flow into the evaporator; when the control board loses communication with or receives an out-of-range signal from the EEV stepper motor driver, E00 triggers. The cabinet cannot maintain proper superheat and will likely shut the compressor down to protect the refrigerant circuit.

Symptoms

  • E00 fault code displayed on the control panel with red status LED illuminated.
  • Compressor cycles off; cabinet temperature rises above setpoint.
  • Buzzer sounds to alert operating staff.
  • Goods room temperature alarm may follow if cabinet stays warm.

Common causes

  • Wiring harness between control board and EEV stepper motor damaged or disconnected.
  • EEV stepper motor coil failure.
  • Control board (PCB) fault preventing EEV drive output.
  • EEV mechanically seized or jammed in closed or open position.
  • Supply voltage interruption during EEV positioning cycle.

Ask the AskWhiz AI about AHT Cooling Systems E00

AskWhiz bot

AskWhiz

online

Hi — I'm the Refrigeration demo. Ask me anything in this domain.

Diagnostic steps

  1. Record fault and move goods

    Note the fault code and transfer perishable goods to another cabinet at the correct product temperature class to prevent loss.

  2. Check EEV wiring connections

    Inspect the connector between the control board and EEV stepper motor for loose pins, corrosion, or broken wires. Reseat connectors and inspect for damage.

  3. Measure EEV coil resistance

    Using a multimeter, check the resistance across each stepper motor winding pair on the EEV. Compare to the specification in the AHT service instructions; an open or shorted coil confirms EEV motor failure.

  4. Inspect control board output

    Verify the control board is outputting the correct drive signal to the EEV. A dead output channel indicates board replacement is required.

  5. Replace defective component

    Replace the EEV stepper motor, the EEV assembly, or the control board as indicated by testing. Use only AHT-approved spare parts.

  6. Test and recommission

    After repair, power the cabinet, confirm E00 clears, and allow 2 hours of trouble-free operation before reloading goods.

When to call a professional

EEV replacement and control board work require an AHT-authorized service technician. Work on the refrigerant circuit requires personnel certified for the applicable refrigerant (R-290 or R-134a). Contact the AHT service line at 00800/73783248 or via www.aht.at/service. Do not attempt to open the refrigerant circuit without proper certification and recovery equipment.