LR3 Connect Flashing red light

Hi, I have a Litter robot 3 Connect. I’ve had it for about 3 years. It has been working fine with the usual faults caused by overweight globe or full bin that have been cleared up every time with simple cleaning/maintenance. The problem I have now is that the red timing light will not stop flashing. When I disconnect the cat sensor and jumper the harness, the robot works fine but lacks the cat sensor so I have to manually press the cycle button each time I want it to cycle.

I purchased a replacement cat sensor in July from robot shop Order 1113555. I just finally got around to installing it and the red light just will not stop flashing still. I left 1mm under the nut as instructions have indicated. I took the globe out and tried to make it cycle. nothing. I was very gentle tightening the nut so as to not crush the new sensor. With the new sensor connected, it just refuses to work at all. Flashing red light only.

Thank you so much in advance for your help!

Hello @bsmith0423 ,

Welcome to RobotShop community.

We are sorry to hear that you are having trouble with your Litter-Robot.

Does the robot work normally if you disconnect the new CAT sensor as you did with the older one?

Is this a normal robot or you have upgraded it to the connect version?

Awaiting your reply.


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Hello, I did purchase a new cat sensor from robot shop to try to fix my red flashing light. I determined that I needed a new cat sensor by unplugging the original sensor and plugging in a jumper to bypass it. This resulted in a solid blue ready light. I replaced the sensor, tightened the nut per instructions and I get the same flashing red light. I again jumpered out the sensor and the solid blue ready comes on. I tried changing the tightness of the nut all the way tight and loosened it a bit, resetting the robot with each adjustment and I can’t get the robot to recognize the cat sensor no matter how I adjust it. What are the chances the replacement sensor is faulty? should I try another replacement?

I’ve been manually pressing the cycle button for months and I’m ready to get this solved.

This is a normal LR3 connect that has not been upgraded.

Hello @bsmith0423,

Welcome back to RobotShop community.

We are sorry to hear that you are still having trouble with your Litter-Robot.

If the red light is still blinking after replacing the CAT sensor and this is a connected version of the Litter-Robot… it’s recommended to replace the circuit board.

Awaiting your reply.


I thought that by jumpering the CAT sensor connector it would confirm the board is good and the sensor bad. This is a pricy board to replace for troubleshooting. If the board does not fix the issue will robot shop accept a return?

Best regards,

Hello @bsmith0423.

Thank you for your reply.

The return policy is 30 days since the purchase so if the circuit board didn’t fix the issue, you can indeed return it.

Awaiting your reply.


ok, very good. I think I will purchase the new board soon. Thank you for your support.

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You are welcome, let us know how it goes.