How to set a deadband so while the zone air temperature is between 22 and 26°C the heating system is off.Am using designbuilder so maybe I can do this through an EMS file

edit

The ELSEIF doesn't make sense. If AvailSCH_Overwrite = 0 && something else, SET AvailSCH_Overwrite = 0 ??

IF AptTemp > (hSP), SET AvailSCH_Overwrite = 0,
ELSEIF AvailSCH_Overwrite == 0 && AptTemp >= (hSP) && AptTemp <= (hSP + Toffset), SET AvailSCH_Overwrite = 0,
ELSE, SET AvailSCH_Overwrite = 1, ENDIF

The program should instead do:

IF AvailSCH_Overwrite == 0 && AptTemp < (hSP), SET AvailSCHOverwrite == 1,
ELSEIF AvailSCH_Overwrite == 1 && AptTemp > (hSP+Toffset), SET AvailSCHOverwrite == 0,
ELSE SET AvailSCHOverwrite == NULL;

If this question is related to the linked one than you need first to set the heating setpoint to 26C and an EMS control logic will be similar to the code desribred here

This is the code which should work in your case

Schedule:Constant,Cycle,OnOff,1; ! New schedule object

AvailabilityManager:Scheduled, ! Updated Availability Manager
  Packaged Rooftop Air Conditioner Availability Manager, 
  Cycle;

EnergyManagementSystem:Sensor,
  AptTemp,
  BLOCK1:ZONE1,
  Zone Mean Air Temperature;

! Don't forget to set heating setpoint to 26C
EnergyManagementSystem:Sensor,
  hSP,
  BLOCK1:ZONE1,
  Zone Thermostat Heating Setpoint Temperature;

EnergyManagementSystem:Actuator,
  AvailSCH_Overwrite,
  Cycle,
  Schedule:Constant,
  Schedule Value;

EnergyManagementSystem:ProgramCallingManager,
  Supervision,
  BeginTimestepBeforePredictor,
  HVAC_uncontolledloop_Supervision;

EnergyManagementSystem:Program,
  HVAC_uncontolledloop_Supervision,
  SET Toffset = 4,
  IF AptTemp > (hSP - 0.01), ! -0.01 due to system can maintain the zone temperature very close to the setpoint
  SET AvailSCH_Overwrite = 0,
  ELSEIF AvailSCH_Overwrite == 0 && AptTemp >= (hSP - Toffset),
  SET AvailSCH_Overwrite = 0,
  ELSE,
  SET AvailSCH_Overwrite = 1,
  ENDIF;