Damper Failed to Close
Damper open. Voltage should not be present on P6-5. Control, vent damper or wire harness is defective. While the Err 56 is displayed by the control, perform the following tasks:
-Remove the call for heat (adjust thermostat or remove wire from TT terminals.
-Check for 24Vac between P6-5 and ground.
-If voltage not present, attempt to start boiler again.
-If 24Vac is present, unplug the vent damper harness from control.
-With wire harness unplugged, check for 24Vac between P6-5 (on Control) and ground.
-If voltage present, replace the control.
-If voltage not present, failed vent damper or wiring harness.
-Check wiring harness for shorts or mis-wiring. Replace if defective.
-If harness not defective, replace vent damper.
