High Temperature 1/2/3 — Discharge Over-Temperature Fault

Common Symptoms

• WS display shows High Temperature 1, 2 or 3 and the machine faults (red LED)
• Compressor shuts down and stays inoperative until cleared

Probable Causes (Ranked by Likelihood)

• Compressor fluid level low High
• Cooler fins or tubes dirty / plugged High
• Thermal valve fault Moderate
• Low water flow or high water temperature (water-cooled units) Moderate
• Ambient temperature above 105°F (41°C) Moderate
• Temperature probe or sensor failure Low

Step-by-Step Diagnostic Procedure

1. The WS Controller is fitted to Sullair STATIONARY electric shop compressors. Portable towable Sullair units (185-class and similar) use different engine-driven controls and a different fault system — this page does not apply to them.

2. Replenish compressor fluid to the proper level — the factory list starts there.

3. Clean the cooler fins and fan blades; on water-cooled machines check for a closed valve, stopped pump or broken pipe, and increase water flow or lower water temperature as needed.

4. Check thermal valve operation.

5. If ambient exceeds 105°F (41°C), improve local ventilation.

6. If the machine is genuinely cool and the fault repeats, check the temperature sensor and its wiring.

7. Factory limits for this condition: T1 warning 225°F; fault 235°F (time-delayed) / 255°F (immediate)

8. Per the factory manual: after resolving a fault condition, press the STOP pad to clear the FAULTED state. If the problem persists after the recommended checks, consult your Sullair distributor or factory service.

Frequently Asked Questions