The Step Test is used to test all major functions of the AIRSYS WPUs: 

  1. Supply Fan
  2. Heater
  3. Mechanical Cooling (Compressor)
  4. Free Cooling/Outside Damper (Economizer Mode) 

You do not need to perform the steps of the test in order. Follow the instruction below to access the Step Test.

  1. From the default display, press and hold Up and Sel together for 3 Seconds
  2. If the system was in automatic mode, the screen will display Sft. Press Up from Sft to reach COd. If the system was not in automatic mode, the screen will display COd without having to press Up
  3. From COd, press Sel to display the current step
  4. Use Up or Down to change the step and press Sel to confirm. Once confirmed, the screen will revert to COd and selected step will start





Supply Fan

Full speed after few seconds



May take up to 1 min to feel warm air



Must run a minimum  of  1min


Free Cooling/Outside Damper

When lights are off, indirect daylight can be seem via opening behind exhaust grill


Repeats for 2nd Unit

Same as 1-4

Important: Step Test takes the system out of automatic mode (if on). Always turn the system back to ON at main menu after the Step Test. For instructions on turning your HVAC system on, refer to Turning your HVAC System On/Off