Soleus Air portable AC stops cooling and shows E4; unit may beep and fan may continue running.

Safety: Turn the unit off and unplug it before draining water to avoid electrical shock.

• Drain the tank: Move the unit to a location where water spillage is acceptable. Remove the lower drain cap or rubber plug at the back or bottom of the Soleus Air portable AC. Place a shallow pan or tray under the drain and allow all water to drain out.
• Check float switch: After draining, remove the rear panel (if accessible) to locate the float or water level switch in the condensate reservoir. Ensure the float moves freely up and down and is not stuck by dirt or scale.
• Clean the reservoir: Wipe out any slime, algae, or debris from the water tank area. Use a mild detergent and rinse thoroughly. Make sure the float magnet and switch area are clean.
• Inspect wiring: Confirm the float switch wires are intact and firmly connected to the control board.
• Optional continuous drain: If your model supports it, attach a drain hose to the continuous drain port and route it to a floor drain to prevent future tank-full shutdowns.
• Restore power: Reinstall the drain cap, reassemble panels, plug the unit back in, and restart. The E4 code should clear once the float switch is in the low position.