Zodiac Robotic Pool Cleaner Troubleshooting Guide

Zodiac Robotic Pool Cleaner Troubleshooting Guide

Zodiac pool cleaners are prone to developing occasional problems, just as with other pool cleaning machines. In some cases, it can be hard to diagnose and remedy these problems on your own.

In this guide, we discuss some common issues with popular models of zodiac robotic pool cleaners and offer advice for how to troubleshoot and remedy problems you may be experiencing.

Troubleshooting With Zodiac Robotic Pool Cleaners

This troubleshooting guide is designed for the Zodiac CX20/CX35 and the Zodiac TX20/TX30/TX35 models. Because most troubleshooting features overlap between these models, we have combined the list into one. Any features that are specific to a certain model will be noted in the following guide.

Troubleshooting Specific Issues

Cleaner Does Not Stay Grounded To The Pool

If this happens to your machine, there is either air trapped inside of the machine or the filter unit is full and/or dirty. To fix this, retrieve the machine from the pool, then clean the filter if needed. Afterwards, resubmerge your cleaner according to the manual.

Cleaner Will Not Climb Pool Walls

If your machine is not climbing, the filter canister may be full or dirty, or there may be algae on the walls of your pool. To fix this, remove the machine and clean the filter.

You should also inspect the walls of your pool for algae, which could be invisible but may still retain a slimy texture that impacts your machine’s ability to climb.

If you find algae or a slimy texture, follow the instructions in this guide on removing algae stains from pool walls while the cleaner is out of the water.

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Zodiac Pool Cleaner Not Moving

If your cleaner stalls upon startup, it is experiencing issues with the power connection. Ensure that the power outlet you are using with the machine is functioning properly.

You should also remove the cleaner from the pool, turn the wheels manually, and then disconnect the control box for 20 seconds.

Floating Cable Becomes Tangled During Cycle

If the floating cable becomes tangled during the cleaning cycle, there could be too much or too little cord in the pool.

To fix this, only use as much cable as is needed to cover your pool’s area, and leave unused cable on the side of the pool.

Ensure that the floating cable enters the water near the middle of the length of your pool; this helps the machine’s mapping software and therefore prevents cord tangling.

Poor Cleaning Performance

If you are experiencing poor cleaning performance, the machine may have worn out brushes, a full/dirty filter, a kinked floating cable, or tire tracks coming off the wheels.

To fix this, replace the brushes if they have become smooth or if the “wear” indicator shows. You should also empty and clean your filter canister thoroughly.

To fix a kinked cable, straighten it out and lay it in the sunlight while working out the kinks. Ensure the cable is not tightly coiled during storage, and make sure it is spread-out and floats on the water when using the machine.

Understanding The Informational LED Light

LED Flashes Once

If the informational LED light on your control box flashes one time with a one second interval, it signifies a connection error between the control box and the cleaner. To fix this, unplug the power cord from the control unit, wait a few moments, and then plug the cord back in.

LED Flashes Twice

If the light on your control box flashes twice in a one second interval, it indicates a problem with the wheels of the machine. To fix this, shut off the machine and retrieve it from the pool. Then, inspect the tire tracks, wheels, and brush components of the machine for any damage or debris.

LED Flashes Three Times

When your LED indicator on your control box flashes three times in a one second interval, this indicates a problem with the impeller, pump axis, or filter unit. To fix this problem, retrieve the machine from the pool and inspect the pump axis and impeller for debris. You should also clean the filter.

LED Flashes After Startup

If the LED indicator on your control box flashes just after starting the machine, there are a few different causes for this. These include cord disconnections, jammed impeller units or wheels, or an improperly submerged cleaner.

To fix cord issues, disconnect and reconnect the floating cable from the control box. An improperly submerged cleaner should be brought to the surface, emptied of water, and then resubmerged following the instructions in your product manual.

Jammed impeller units and/or wheels should be inspected and cleaned of any debris. If this does not fix the problem, contact Zodiac customer services.

LED Flashes During Cleaning Cycle

If the light on your control box flashes during the cleaning cycle, it means that the cleaner may be sucking in air. To fix this, bring the cleaner to the surface and drain it of water completely. Then, resubmerge it according to the instructions in the manual.


If all else fails, get in touch with Zodiac support directly. They will do their best to help you, and can arrange for repair of your unit if necessary.

They can also assist with any other Zodiac models, including the FX18.

Louis from Pool Advisor


A chemical engineer by trade, Louis is committed to debunking myths in the pool industry by explaining the underlying chemistry and making it accessible to all.