Oil Purifier Not Pumping Oil: Troubleshooting Guide

An oil purifier failing to pump or draw oil is a common issue. Since it involves a complete oil circuit, a problem at any point can cause this failure.

Please don't worry. We can troubleshoot by following a logical sequence, from simple to complex, and external to internal.

 Step 1: Quick Checks (The Most Common Causes)

1.  Power Supply and Motor Rotation:

       Is the power on? Check the main switch, plug, and fuses.

       Is the motor rotation correct? For 3-phase purifiers, if the motor rotates in reverse, the pump cannot create suction. It often sounds noisy and weak. Correct the rotation by swapping any two power phases.

2.  Initial State and Piping Connections:

       Is the pump primed? Centrifugal and gear pumps require the pump cavity to be filled with oil to create suction. If used for the first time or after a filter change, the cavity might be empty. Check if the machine has a "priming port" or "vent valve" and prime it according to the manual.

       Are the inlet/outlet hoses connected correctly? Ensure the suction hose is connected to the inlet and the discharge hose to the outlet. Reversed connections will prevent operation.

       Is the suction hose leaking air? This is a top common cause of failure! Check all connections on the suction hose. Ensure quick-connect seals are tight, and not aged or damaged. Any tiny air leak will break the vacuum and prevent suction.

3.  Condition of the Source Oil:

       Is the oil temperature too low? If the oil is too cold (e.g., in a freezing environment), its viscosity becomes very high, making it difficult for the pump to draw. Preheat the oil or use the machine's built-in heater.

       Is the suction inlet blocked? Check if the strainer at the end of the suction hose or the machine's inlet is clogged with sludge or debris from the tank bottom.

 Step 2: Component-Specific Deep Checks

If the problem persists after Step 1, you need to inspect the core components. Please refer to the following diagnostic flowchart:

The core troubleshooting points based on the chart are:

1. Diagnosing with Gauges

   Situation A: High Reading on the Inlet Vacuum Gauge

       Fault Cause: Blockage in the inlet pipeline or components. The pump is "working hard" but oil cannot flow through.

       Checkpoints:

           Clogged suction strainer.

           Severely clogged inlet coarse filter (strainer). This is a very common cause, especially when processing dirty oil.

           Inlet valve is closed or damaged.

           The inlet pipe is kinked or crushed.

   Situation B: High Reading on the Outlet Pressure Gauge

       Fault Cause: Blockage in the outlet pipeline. The pump is pushing oil, but the path is blocked.

       Checkpoints:

           Severely clogged final filter (cartridge). This is the most likely cause! A spent filter cartridge creates high resistance and must be replaced.

           The outlet valve is closed.

           The outlet pipe is kinked or crushed.

           The inlet of the target tank is too high or blocked.

   Situation C: All Gauges Show No Response, Pump is Freewheeling

       Fault Cause: The problem is likely with the pump itself or a severe air leak on the inlet side.

       Checkpoints:

           Pump damage (e.g., severely worn gears in a gear pump, excessive clearance, no suction).

           Damaged pump shaft seal, causing a major air leak.

           A large crack in the suction hose or a disconnected joint.

 Summary and Action Plan

When your oil purifier is not pumping oil, please follow this sequence:

1.  Turn off the power for safety.

2.  Visual Inspection: Power, rotation, hose connections, air leaks, valve positions.

3.  Check the Oil: Is the temperature too low? Is the viscosity too high?

4.  Check the Filters: The coarse strainer and final filter cartridges are the primary suspects, especially if the machine has been in use. Replacing the filter cartridge is one of the most efficient troubleshooting steps.

5.  Observe the Gauges: Use the readings from the vacuum and pressure gauges to determine if the problem is on the inlet side, outlet side, or the pump itself.

6.  Finally, inspect the Pump: If all the above are correct, the pump is likely internally worn and needs repair or replacement by a professional.

In most cases, the issue lies in air leaks in the hose, clogged filters, or incorrect initial setup. We hope this guide helps you resolve the problem quickly!