PETKIT Purobot Ultra stuck on trash bag not refilled
- Read the exact wording — "double click OK" means you likely already have a usable ring — don't replace it again.
- Check the recharge ring is seated — remove the ring cover, insert the ring, refit the cover.
- Double-press OK to confirm — the Purobot Ultra needs this manual confirmation before it resumes auto-refilling on its own.
- Check the litter collection trays — "Trunk not installed" blocks the same workflow and is easy to mistake for a ring problem.
- Message won't clear — the panel keeps scrolling "Trash bag not refilled, please double click OK button to start auto-refilling" even after you installed a fresh recharge ring.
- No auto-packing — the litter box stopped sealing and bagging waste automatically, even though it used to work fine.
- Similar-sounding warnings — you're also seeing "Out of trash bag soon" or "Out of trash bag, please replace the refill ring now" and can't tell which one applies.
Your cat can still use the box, but cycles aren’t reliable. Scoop once by hand today so waste doesn’t sit in the globe overnight.
Why the message won't clear on its own
The Purobot Ultra's auto-refill system is built around a manual checkpoint, not full automation — and that single design choice is behind almost every report of this message sticking around.
A confirmation step, not a ring fault
PETKIT's manual is explicit: after removing a sealed bag or fitting a new ring, you have to double-press OK to start auto-refilling. The box doesn't detect a fresh ring on its own and resume — it waits for that confirmation indefinitely.
Three lookalike messages
The scrolling status area cycles between an early ring warning, an empty-ring warning, and this confirmation prompt. They read similarly at a glance but call for different actions — replacing a ring that isn't actually the problem wastes a ring and doesn't fix anything.
In most cases, the steps below get auto-refilling running again in under ten minutes.
How to restart auto-refilling
Work through Part A to confirm the ring itself, then Part B to send the confirmation the box is waiting for.
Keep a spare recharge ring in the house
Running out mid-week is the most common reason owners end up troubleshooting this at an inconvenient time.
If the issue persists: replacement options
If the message won't clear after a confirmed ring, a double-pressed OK, and properly seated trays, replace the ring with a fresh one — a ring that's been sitting unused for a long time can arrive with fewer usable bags than expected.
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If replacing the ring and confirming still doesn't restart auto-refilling, the advanced section below covers the two edge cases most likely to be the real cause.
Advanced: the three messages, and a full waste bin
Two situations account for most of the remaining reports.
The three trash-bag messages, side by side
"Out of trash bag soon, please replace the refill ring in time" is an early warning — the ring still has bags left, no action needed yet. "Out of trash bag, please replace the refill ring now" means the ring is empty and needs replacing. "Trash bag not refilled, please double click OK button to start auto-refilling" is different from both: it means a ring is (or should be) installed, and the box is waiting for your confirmation before it resumes. Mixing these up leads to replacing a ring that didn't need it, or missing the double-press step entirely.
Why the box pauses emptying when the waste bin is full
PETKIT's manual documents this directly: if the waste bin is full while you're emptying the cylinder, the Purobot Ultra stops emptying and switches to auto-packing instead. Once you remove the sealed bag, the unit continues where it left off. If you see this sequence, the box is waiting on you to take out a full bag — it isn't stuck or malfunctioning.
| Message | What it means | Action |
|---|---|---|
| Out of trash bag soon | Ring running low | Have a new ring ready, no rush |
| Out of trash bag, replace now | Ring empty | Replace the ring |
| Trash bag not refilled, double click OK | Waiting for manual confirmation | Double-press OK on the panel |
| Trunk not installed | Litter collection tray loose | Reseat trays #1 and #2 |
Frequently asked questions
Why does my PETKIT Purobot Ultra say "trash bag not refilled" after I replaced the ring?
Because the box needs a manual confirmation, not just a fresh ring. Press the menu button to select the icon shown on screen, then double-press OK to actually start auto-refilling.
How do I start auto-refilling on a PETKIT Purobot Ultra manually?
Confirm the recharge ring is seated, then double-press OK on the control panel. The Purobot Ultra does not resume auto-refilling on its own after a ring swap or a bag removal.
What's the difference between "out of trash bag" and "trash bag not refilled" on a Purobot Ultra?
"Out of trash bag" (soon or now) means the ring itself is low or empty. "Trash bag not refilled, double click OK" means a ring is in place and the box is waiting for your confirmation to resume — it's not a ring problem.
Why won't my Purobot Ultra auto-pack even with a new ring installed?
Check that the #1 and #2 litter collection trays are fully seated — a loose tray triggers a separate "Trunk not installed" message that blocks auto-packing the same way a ring issue would.
Conclusion
"Trash bag not refilled, please double click OK" is a pending confirmation, not a broken ring, in most cases. Replace the ring only if it's genuinely empty, double-press OK to tell the Purobot Ultra to resume, and check the litter collection trays if that still doesn't start it.
Still not fixed? Here’s what to do next.
Some faults are genuinely hardware, and no amount of cleaning or resetting will clear them. If you’ve worked through everything above and it’s still doing it, stop here rather than taking the unit further apart.
- Go to PETKIT directly. If the unit is still under warranty, let them replace the part rather than paying for it yourself — contact PETKIT support.
- Tell us what didn’t work. We rewrite bulletins when readers show us a case they don’t cover — compliance@pet-infrastructure.com. Tell us the model, what the lights are doing, and which steps you already tried.
- Ask other owners. Search Reddit for your model name plus the symptom (for example “PETKIT Purobot Ultra not cycling”). Someone has almost certainly hit the same fault, and owner threads often surface fixes before the manufacturer documents them.
When to stop and call the manufacturer: if the fix needs the base opened, the motor or control board touched, or any tool beyond a screwdriver — stop. On a unit in this price range, opening it yourself usually voids the warranty, and a warranty repair costs nothing.
Did this actually fix it? 🐾
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Written by Alberto Guardia
I’m a physician working in medical informatics, and I run Pet Infrastructure on my own — no team, no manufacturer sponsorship, no paid placements. I share my home with Wolfgang, a 13-year-old Chartreux with firm opinions about litter and none whatsoever about firmware.
How this page was put together. Every light code, button sequence and timing here is traced back to PETKIT’s own documentation, to official support articles, or to several owner reports that agree with each other — and the guide tells you which. Where something genuinely isn’t documented anywhere, I say so instead of filling the gap.
How I check every guide → · Last updated August 2026