Code 22 — Furnace Flame Sense Error

What does 22 mean?

This fault indicates that the furnace's flame sensor is not detecting a flame after ignition, or it's detecting one when it shouldn't. This prevents the furnace from operating safely.

• Dirty or corroded flame sensor
• Faulty flame sensor
• Weak or inconsistent flame
• Poor ground connection to the furnace

Click steps to track your progress.

1. 1

   Turn off the power to the furnace at the circuit breaker.

2. 2

   Visually inspect the flame sensor (if accessible and you feel comfortable) for obvious dirt or corrosion. Do not attempt to clean if unsure.

3. 3

   Restore power and observe if the furnace attempts to ignite.

4. 4

   If the error continues, a qualified HVAC technician is needed to inspect or clean the flame sensor.