H21 — Drainage blocked or float sensor defective

What does H21 mean?

The condensate drainage system is blocked, or the float sensor is not working correctly. This prevents water from draining, potentially causing overflow.

• The drain pipe is clogged.
• The drain pan is full.
• The float sensor is malfunctioning or stuck.
• Condensate pump failure (if applicable).

Click steps to track your progress.

1. 1

   Check and clear any blockages in the condensate drain pipe.

2. 2

   Ensure the drain pan is not overflowing.

3. 3

   Inspect the float sensor for proper movement and function.

4. 4

   If a pump is present, verify its operation.

5. 5

   Turn off the unit, unplug it, wait 30 seconds, and plug it back in to reset.