Code 33 — Limit Circuit Fault (high heat only)

What does 33 mean?

A fault has been detected in the limit circuit specifically when the system is operating in high heat mode. High heat operation will be disabled.

• Overheating during high heat operation
• Faulty limit switch
• Restricted airflow during high heat
• High heat component issue

Click steps to track your progress.

1. 1

   Ensure air filters are clean and airflow is not restricted.

2. 2

   Check that all system vents and registers are open.

3. 3

   Verify the system is not set to excessively high temperatures.

4. 4

   Contact an HVAC technician if the issue persists during high heat.