Aprilaire dehumidifier shows E5 and stops running

Safety first: Disconnect power before opening the cabinet or handling water.

• Check drain line: Inspect the condensate drain hose or PVC line for kinks, clogs, or upward loops that trap water. Clear any obstructions and ensure a continuous downward slope.
• Verify unit is level: Use a level on top of the dehumidifier. Adjust feet or shims so the unit is slightly pitched toward the drain outlet.
• Inspect float switch: Open the access panel to locate the condensate pan and float switch. Manually lift and lower the float; it should move freely and click the switch.
• Clean pan: Remove standing water with a wet/dry vacuum. Clean the pan of slime, algae, and debris that can jam the float.
• Test switch continuity: With power off, disconnect the float switch leads and test continuity while moving the float. Replace the Aprilaire float switch assembly if it does not change state.
• Restore power: After clearing water and verifying drainage, restore power and confirm the E5 code clears and normal operation resumes.