Code 45 — Control failure / Control Circuitry Lockout

What does 45 mean?

This code points to a failure within the system's control circuitry. This can prevent the system from operating correctly.

• Control board malfunction
• Wiring issue in the control circuit
• Power supply problem to the control board

Click steps to track your progress.

1. 1

   Check all control wiring connections for tightness and damage.

2. 2

   Ensure the control board is receiving proper voltage (24VAC).

3. 3

   If the problem continues, a control board replacement may be necessary.

4. 4

   Contact an HVAC technician for further assistance.