H99 — Indoor operating unit freeze protection (Cooling)

What does H99 mean?

The system has detected potential freezing in the indoor unit during cooling operation. This is often due to restricted airflow.

• Indoor heat exchanger is dirty
• Air filter is dirty
• Short circuit in air circulation
• Low ambient temperatures during cooling operation

Click steps to track your progress.

1. 1

   Clean the indoor heat exchanger.

2. 2

   Clean or replace the air filter.

3. 3

   Ensure there are no obstructions to the indoor unit's air circulation.

4. 4

   Verify the unit is not operating in excessively low temperatures for cooling.