Chigo EEPROM / Memory Error on Indoor PCB

Indoor unit displays H4 and the system may not start; sometimes after a power interruption.

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Possible Causes

Corrupted EEPROM data on Chigo indoor main PCB, Faulty indoor PCB, Voltage surge or spike damaging memory

Safety first: Turn off power before accessing the indoor PCB.

Step 1 – Power cycle: Turn off the breaker for 10 minutes to fully discharge the board, then restore power and check if H4 clears.
Step 2 – Surge protection: If H4 occurred after a storm or power surge, consider installing a surge protector for the AC circuit.
Step 3 – Replace indoor PCB: If H4 persists, the indoor main PCB is likely defective and must be replaced with a compatible Chigo board.

Hard 4/5

Indoor Main PCB

Check Price on Amazon

We may earn a commission from links on this page.