ACiQ EH00

What does ACiQ EH00 mean?

EH00 indicates an indoor unit EEPROM malfunction, meaning the indoor PCB's main chip is not receiving valid feedback from its EEPROM memory chip. The EEPROM stores the board's operating parameters; when the controller cannot read them correctly, the indoor unit flags EH00. The related EH0A code points to an indoor EEPROM parameter error.

Symptoms

• EH00 shown on the indoor unit display
• Indoor unit fails to operate normally
• Code persists after a power cycle when the board is at fault
• Possible related EH0A parameter-error display

Common causes

• Corrupted or unreadable indoor EEPROM data
• Faulty indoor main PCB or EEPROM chip
• Transient power disturbance that cleared after restart

Diagnostic steps

1. 01

   Power cycle the unit

   Shut off power, wait about two minutes, then restart and check whether EH00 still appears.

2. 02

   Confirm the fault is persistent

   If the code clears after restart, the unit is operating normally; if it returns, the indoor board needs attention.

3. 03

   Inspect the indoor board

   Have the indoor PCB checked, since EH00 traces to the indoor EEPROM not returning valid data to the main chip.

4. 04

   Replace the indoor PCB

   If the code persists, the indoor main control board is the recommended replacement part for an EEPROM malfunction.

When to call a professional

Confirming an EEPROM fault and replacing the indoor control board involves opening the indoor unit and handling electronics where stored capacitor charge can remain after power-off. If a power cycle does not clear EH00, contact a licensed HVAC technician to verify and replace the indoor PCB. Board-level diagnosis and replacement on these inverter systems should be left to a qualified professional.