The indoor unit displays E9, and the unit may shut down unexpectedly.

Safety first: Turn off the indoor unit and disconnect power before working near water and electrical components.

• Check drain hose: Ensure the condensate drain hose slopes downward continuously from the indoor unit to the drain point. Remove any kinks or upward loops.
• Clear clogs: Use a wet/dry vacuum at the drain outlet to suck out sludge and algae. Alternatively, blow compressed air from the indoor side to clear the line.
• Inspect float switch: Open the indoor unit's drain pan area and locate the float switch (if equipped). Make sure it moves freely and is not stuck in the up position. Clean any slime or debris.
• Level the unit: Verify the indoor unit is slightly tilted toward the drain side. Adjust mounting if necessary.
• Test operation: After clearing and cleaning, restore power and run the unit. If E9 persists, replace the float switch assembly.