Rheem ductless mini‑split indoor unit displays E0 and will not operate or responds erratically to remote commands.

Safety first: Turn off the indoor unit, then switch OFF the outdoor disconnect and the breaker feeding the Rheem system. Verify power is off with a non-contact voltage tester before touching wiring.

• Power reset: Leave power off for 5–10 minutes to allow capacitors on the indoor PCB to discharge. Restore power and see if the E0 code clears.
• Check low-voltage connections: Remove the indoor unit front cover. Inspect the wiring harnesses going to the indoor main PCB (often labeled CN1, CN2, etc.). Reseat each plug firmly. Look for bent pins, corrosion, or heat discoloration.
• Inspect for surge damage: Look for burn marks, swollen components, or a burnt smell on the indoor control board. If present, the board is likely damaged.
• Remote control check: Replace batteries in the Rheem remote and ensure it is set to the correct mode. Confirm that the indoor unit receives the signal (beep or LED flash).
• When to replace: If E0 returns immediately after a proper power reset and wiring inspection, the indoor PCB/EEPROM is likely defective and should be replaced with the exact Rheem part number specified for your model.

Warning: Do not attempt component-level board repair unless you are qualified. For persistent E0 faults, contact a licensed HVAC technician to replace and program the correct Rheem indoor control board.