Crown boiler error code 56

Crown boiler error code 56

This error code appears when the vent damper fails to close properly. It happens when the damper, wire harness, or control board are faulty.

How do I fix it?

  • Make sure there is no voltage on P6-5.
  • Adjust the thermostat or disconnect TT terminals.
  • Check the 24Vac power supply between ground and P6-5.
  • If there is no voltage, try to restart the boiler.
  • If the 25Vac is there, disconnect the vent damper wiring from the control board and check the 24Vac between ground and P6-5.
  • If there is voltage, it is a control issue. Replace the control board.
  • If there is no voltage, it is a wire harness or damper issue. If these are faulty, replace or repair them.