Error 153 — Floating switch of indoor unit (2nd detection)

What does 153 mean?

The indoor unit's floating switch, which detects condensate overflow, has triggered for a second time. This indicates a persistent problem with the condensate drain system.

• Clogged condensate drain line
• Faulty float switch
• Condensate pump failure (if applicable)
• Improper installation causing water buildup

Click steps to track your progress.

1. 1

   Turn off the indoor unit immediately to prevent potential water damage.

2. 2

   Check the condensate drain pan for standing water and inspect the drain line for clogs.

3. 3

   Clear any blockages found in the drain line using a wet/dry vacuum or by flushing with water (if safe).

4. 4

   Ensure the float switch is moving freely and is not stuck in the 'up' position.

5. 5

   Restore power once the issue is resolved. If the problem persists, the switch or pump may need replacement.