Whisker Litter-Robot 4 troubleshooting
9 problems the manual covers, with the cause and the fix it gives.
This is a rotating globe box. The steps below are the manufacturer's own; if a step involves opening the unit, check the warranty first.
Light bar flashes blue
Why: The waste drawer is full.
What to do: Empty the drawer, press Reset, then press Cycle.1
Blue light with flashing yellow
Why: The scale has been triggered for more than 30 minutes.
What to do: Remove extra weight, put the unit on level hard floor away from walls, mats and cords, then press Reset.1
Red and blue lights alternate
Why: The curtain (laser) sensors are dirty.
What to do: Clean the three laser sensors.1
Red light with flashing yellow
Why: The globe is jammed or overloaded.
What to do: The unit stops, retracts and retries by itself; clear any obstruction.2
Yellow ping-pong light bar
Why: The anti-pinch sensor stopped the globe.
What to do: The globe retracts for 5 seconds and tries to continue; remove any obstruction.2
Solid yellow light
Why: The unit is paused during a cycle.
What to do: Press Cycle to resume or Reset to abort.2
Flashing yellow light
Why: The bonnet has been removed.
What to do: Put the bonnet back; the unit resumes 5 seconds later.2
Green light with flashing red
Why: Sensor auto-calibration failed.
What to do: Clean the curtain sensors.1
White light with flashing yellow
Why: Wrong power supply.
What to do: Replace with the correct power supply.1
Sources
- Litter-Robot 4: Light codes guide (official support), checked Oct 8, 2026
- Litter-Robot 4 Instruction Manual (Whisker), p. 5, 10, 12, 19, 21, 24, 28, 29, 35, checked Oct 8, 2026