Litter-Robot 3: Cat not detected

The Litter-Robot 3 is equipped with a cat sensor that detects when a cat enters and exits the globe.

To ensure the accuracy and reliability of the cat sensor, press the Reset button after making any changes that will affect the weight of the unit, including emptying the waste drawer, adding or removing litter from the globe, or cleaning or moving the unit.

It's important to note, that your cat must weigh at least 5 pounds to activate the cat sensor. Do not use the Litter-Robot in automatic mode with kittens that weigh less than 5 pounds. 

The cat sensor may also not activate when a curious kitty puts weight on the step or in the front of the globe without completely entering the unit.

If your Litter-Robot is not detecting your cat, there are several things we need to check.

Check for obstructions

Check for obstructions that might prevent the cat sensor from functioning. 

  1. Make sure the Litter-Robot is on a firm, level surface. The cat sensor function can be affected if the unit is on carpeting or a litter mat.
  2. Check that there are no power cords running underneath the base of the robot that might obstruct movement.
  3. If the Litter-Robot is on a slippery surface like tile or a wood floor, it may shift over time and come in contact with a wall or furniture.
  4. Make sure your unit is at least one inch away from walls and furniture.

Check your sleep mode settings
  1. Ensure your unit is not in 8-hour sleep mode. If sleep mode is active, both the blue and yellow lights will be illuminated.


  2. Sleep mode is useful for units located in bedrooms or areas where you may not want the unit to cycle for a period of 8 hours.
  3. To disable sleep mode, long press the Cycle button for 3 seconds. This also enables sleep mode.

Sleep mode can also be enabled or disabled from the Whisker app.


Inspect the litter and waste drawer
  1. Next, empty the waste drawer. It's best to empty the waste drawer if it's getting close to full.
    If you use the Whisker app, press Reset Gauge in the Controls section of the app when you empty the waste drawer to reset the waste drawer level in the app.
  2. Check for excess litter inside the globe. Using more than 10 lbs of litter can trigger the cat sensor, causing your cat to not be detected.
  3. Make sure the litter is at or below the raised fill line. Some brands of litter are heavier than others. For these litters, we recommend keeping the litter at least a half inch below the fill line to avoid weight-related errors. Do not use lightweight litter, as this could affect the unit's ability to detect the cat.
    Always remember to push the Reset button after making changes to the unit. This will recalibrate the weight sensor and circuit board to reflect the changed weight.
  4. From the Home position, press the Power button to turn the unit off.
  5. Press the Power button to turn the unit back on. Litter-Robot will perform an initial Clean cycle, and the cat sensor will take a new measurement of the unit's weight.

Success: The Litter-Robot should return home displaying a blue 'ready light' status.

Unsuccessful: If your unit is not displaying a solid blue light after returning to home position, or cannot complete the cycle, please continue with troubleshooting.


Test the cat sensor

Test the cat sensor by pressing the top of the entryway (not the bonnet), down and away, toward the back of the unit.

You should be able to feel a slight spring/bounce movement - this is a good sign that the robot can freely move and that there are no obstructions to prevent the cat sensor from functioning.

Success: The light should switch to red, as if recognizing your cat's entry into the unit.

Unsuccessful: If your unit is not displaying a solid red light after testing the cat sensor, please continue with troubleshooting.


Check the cat sensor connection

Next we'll check the cat sensor connection, which might have accidentally been knocked loose while transporting or cleaning the unit.

  1. Remove the bonnet by pressing the latches on both sides of the bonnet, then lift while rotating it backward. There are two plastic tabs on the back of the bonnet that should slide up and out of the base.
  2. Set the bonnet aside.
  3. Remove the globe and set aside.
  4. Remove the waste drawer and set aside.
  5. In the back of the base is the cat sensor module. Check the cat sensor connection to ensure that the sensor in the base is connected to the wiring harness in the rear of the unit.

  6. Now you can reassemble your Litter-Robot.
  7. Reinstall the waste drawer.
  8. Replace the globe, making sure it is on straight and in its tracks.
  9. At the back of the globe, turn the black key into the key pocket.
  10. Replace the bonnet by inserting the bonnet tabs into the rear bonnet slots, then press the latches while rotating it forward, until the latches click into place.

Cleaning your Litter-Robot

It's important to deep clean your Litter-Robot every 3-6 months.

Over time, small clumps can accumulate within the internal pocket of the globe, which can contribute to weight-related errors.

Cleaning or soaking the globe thoroughly every 3-6 months will help prevent any excess weight from accumulating within the globe.

Customers with more than one cat may want to perform globe cleanings more frequently.


Issue not resolved? 

If you've completed this troubleshooting and your Litter-Robot is still not detecting your cat, you need to replace your base.

What do I do?

My unit is covered by WhiskerCare™

If your Litter-Robot is covered by our WhiskerCare™ warranty, you have access to replacement parts, at no cost. Please contact Whisker Customer Support.

The warranty on my unit has expired

If your unit is no longer under warranty, we can help you with the necessary parts and instructions to properly fix your unit at home. 

Parts Needed: 


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