High Pressure Lockout for 4 Hours 84

What does 84 mean?

The system is locked out for 4 hours due to persistent high pressure events. This can be caused by various factors including an overcharged system, airflow restrictions, closed service valves, or a faulty high pressure switch.

• Outside Normal Operating Range (e.g. improper load calculation, system match issue, outside cooling range, outside heating range etc)
• Loose High Pressure Switch harness leads
• Pressure Switch disconnected from ODU Control Board
• Faulty Pressure Switch
• Overcharged System
• Outdoor Airflow too low or off
• Service Valve left closed (Liquid or Vapor)

Click steps to track your progress.

1. 1

   Check the High Pressure Switch (HPS) harness leads for looseness and ensure the switch is connected to the ODU Control Board.

2. 2

   Ensure all service valves (liquid or vapor) are fully open.

3. 3

   Inspect the outdoor coil for clogging (ice or debris) and clean or de-ice if necessary; troubleshoot the outdoor fan motor.

4. 4

   Check the system charge using Cooling Charging Mode; if overcharged, adjust the refrigerant level.

5. 5

   If the discharge pressure is less than 610 +/- 20 psig and the HPS is open (measure resistance), replace the pressure switch.