Refill For Purobot Ultra: When and How to Replace

By PETKIT UK | Published: 2026-10-26

Category: How-to Guides

Learn when to replace the refill for your Purobot Ultra and follow our step-by-step guide to ensure smooth, hassle-free operation of your self-cleaning litter box.

Quick answer

Replace the refill ring for your Purobot Ultra when the app or indicator light notifies you that the bag cartridge is low or empty. Use only PETKIT's exclusive refill ring with the sensing chip, or the auto-seal function will not work.

Why the exclusive refill matters

The Purobot Ultra's auto waste packing system relies on a sensing chip inside the refill ring to detect whether a cartridge is installed. If you use a non-PETKIT bag or a reused ring, the system cannot confirm the cartridge is present and will refuse to seal the trash bag. This is a safety feature, not a limitation. Sticking to the official refill ensures every cycle completes without interruption.

Signs it's time to replace

The Purobot Ultra will alert you through the PETKIT app or a flashing indicator light when the bag cartridge is nearly empty. Do not wait until the bag runs out mid-cycle—replace the refill as soon as you see the notification. A full cartridge typically lasts several weeks depending on your cat's usage, so checking the app weekly helps you avoid surprises.

How to replace the refill ring on your Purobot Ultra

1. Open the waste compartment: Press the release button on the top of the Purobot Ultra to lift the lid. Pull out the waste bin drawer completely. Place it on a flat, clean surface. Do not force the drawer; if it sticks, check that the unit is powered off.
2. Remove the old refill ring: Grip the used refill ring by its edges and lift it straight up out of the waste bin. Dispose of the ring and any remaining bag material according to local waste guidelines. The ring may have residual litter dust—wipe the bin interior with a dry cloth before inserting the new ring.
3. Install the new refill ring: Take the new PETKIT refill ring and align it with the slot inside the waste bin. Press down firmly until you hear a click, confirming the sensing chip is seated. Ensure the bag cartridge is fully unwound and the open end is accessible. If the ring does not click, remove it and re-align—never force it, as this can damage the chip.
4. Close the compartment and reset: Slide the waste bin drawer back into the Purobot Ultra until it locks. Close the top lid. The unit should automatically detect the new refill. If not, press the reset button on the control panel or check the app to confirm the cartridge status. A persistent 'no cartridge' alert means the ring is not properly seated—repeat step 3.

Product facts

Refill For Purobot Ultra: The auto waste packing system requires the use of PETKIT's exclusive refill ring, which is equipped with a sensing chip to check whether the cartridge is installed. Using any other bag or ring will prevent the Purobot Ultra from auto-sealing the trash bag, leading to manual cleanup and potential mess.
Refill For Purobot Ultra