Code 31-16 High Pressure Switch Shutdown - High pressure switch activated.

What does 31-16 mean?

This fault means the 670psi high pressure switch has activated, safely disabling system operation. It can occur due to rapid pressure spikes or a fault in the high-pressure switch's wiring harness during high-pressure events. The system will not attempt to restart until discharge pressure drops below 425 PSIG.

• Rapid transient high pressure event in the system.
• Break or short in the high pressure switch wire harness.
• Discharge pressure exceeding 670psi.

Click steps to track your progress.

1. 1

   Wait for the system to cool down naturally; operation will resume once discharge pressure falls below 425 PSIG.

2. 2

   Ensure the high pressure switch (HPS) is securely connected to the VFD.

3. 3

   Inspect the wire harness connected to the HPS and VFD for any signs of breaks, shorts, or loose connections.

4. 4

   If the fault persists, contact a qualified technician as it may indicate an internal pressure issue or faulty switch.