This is an instructional guide showing how to perform a back flush of the Portable Control Unit with a garden hose.

If your Portable Control Unit (PCU) is making a grinding noise while it is running (even with water in it), it is possible that some debris has entered the Impeller section causing the grinding sound. 

Note that it is normal for the PCU to make a "grinding" or "clunking" sound when the pump is activated and will go away once it becomes primed and flow is detected out of the heater port in the tub.


Back flushing the PCU is a good practice to carry out every few months to aid in PCU performance and longevity. 

1. Cap the ports inside the tub if you do not want to drain the spa.

2. Unplug the GFCI and disconnect the PCU from the connector hoses.
3. Remove the Filter Housing Lid as well as the filter inside.

4. Use a standard garden hose and insert it into the Heater Port (top right port).

5. Hold the hose in the Heater Port and flush the system for approximately 30 seconds (water will exit from the Filter Port on the left).
6. Turn the PCU upside down to empty the water. Check the discharged water for any debris that has been flushed out.

7. Inspect the Filter Bowl for any trapped debris. Repeat the flushing process if necessary.

8. Reinstall the PCU to the tub and start up as normal.

We also have a video showing how to disconnect the Filter Port and flush any hair that can get trapped inside. Please click here to watch!

To watch our quick video tutorial showing how to perform the PCU back flush, please click here.

If grinding noise is still persistent, please contact Customer Service.