Display shows E9; unit may not cool and may shut down shortly after startup.

Safety: Disconnect power before accessing internal electronics.

• Hard reset: Unplug the Soleus Air AC for at least 10 minutes. Press and hold the POWER button (if accessible) for 10 seconds to discharge residual power, then plug back in and test.
• Check power quality: Avoid using long or undersized extension cords. If your home has frequent surges, consider using a surge protector rated for AC units.
• Inspect PCB: Remove the control panel cover and visually inspect the main board for burn marks, cracked components, or bulging capacitors.
• Board replacement: If E9 persists after reset and there is no visible wiring issue, the main control board is likely defective. Order the exact replacement board for your Soleus Air model and transfer all connectors one by one to the new board.
• Reassemble and test: After installing the new PCB, reassemble the unit, restore power, and verify that the E9 code is cleared and all functions operate normally.