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By Jason Feng, Founder & Researcher. See how this review was researched.
Quick answer
A Litter-Robot 4 globe liner is $70, and it is free once under warranty through the Whisker account. The 5 and 5 Pro liner follows the same design with a shorter teardown.
Replace it when clumps stick to a clean liner, when the rubber has gone tacky, or when odour survives a deep clean. Do not discard the round liner weight when you swap it: the weight is what separates clumps from the rubber, and the new liner has no weight in the box.
Table of contents
- Two liners, two different jobs
- What the globe liner actually does
- Wear signals and what each means
- The warranty path, before you buy
- Litter-Robot 4 replacement, step by step
- How the 5 and 5 Pro differ
- The liner weight
- Which faults a worn liner causes
- Third-party liners
- Replacement interval and annual cost
- Our verdict
- How we researched this
- Sources
Two liners, two different jobs
The word liner covers two consumables on a Litter-Robot, and confusing them is the most common mistake in this part of ownership.
The waste drawer liner is a bag. Whisker lists packs of 10, 25, and 50 at $12, $25, and $35, with autoship prices of $8.40, $17.50, and $24.50. It goes in the drawer and is thrown away at every empty; Whisker notes white bags read more accurately on the drawer-full sensor than dark ones.
The globe liner is a moulded rubber skin bonded into the rotating drum: a part, not a consumable in the bag sense, costing $70 on the Litter-Robot 4, and replacing it means splitting the globe in half. Whisker describes it as an extra durable liner and sells it to owners whose unit is out of warranty.
This article is about the second one. For how often to change the bag, see how often to clean a litter box.
What the globe liner actually does
The liner is a flexible rubber surface inside a rigid drum: flexible, smooth, and securely bonded. Whisker’s installation guide states the mechanism: the globe liner weight helps separate litter clumps from the liner as the globe rotates. The rubber flexes, the weight biases it, and the clump breaks free rather than welding on. A liner that has stiffened stops doing that, and the symptom is clumps that stick through a cycle and have to be scraped.
Flexibility fails with age and harsh chemicals: a liner washed with solvent, or left in a hot car during a move, goes stiff. Surface smoothness fails with scratching. The bond fails at the seams, where the liner folds over the drum edge and the two globe halves squeeze together; Whisker notes the overlapping edge acts as a seal when the halves are reassembled, so a badly fitted liner is also a leaking globe.
Wear signals and what each means
| Signal | What it indicates | Action |
|---|---|---|
| Clumps stick to a liner that was just cleaned | Rubber has stiffened or the surface has dulled | Replace the liner |
| Liner feels tacky or leaves a residue on a cloth | Rubber degrading; often after harsh cleaners | Replace the liner |
| Odour returns within a day of a deep clean | Odour has penetrated the rubber, not the surface | Replace the liner |
| Visible cracks at the fold over the drum edge | Bond failing at the seal | Replace before it tears |
| Tearing at the liner clip or the screw holes | Mechanical damage from a previous install | Replace; a torn liner leaks litter into the globe halves |
| Litter escaping between the globe halves | Liner not seated, or the overlapping edge folded wrong | Reinstall first; replace if the edge is deformed |
| Clumps sticking only in one spot | A worn patch, or a clump welded and left | Clean and observe one week; replace if it recurs |
| Rust on the liner weight | Surface rust on the weight, not a liner fault | Whisker states this does not affect function and is safe to reinstall |
The last row comes straight from Whisker’s guide: rust on the weight is cosmetic, so do not replace a liner over it. The sixth row is the one to work through carefully: litter escaping between the globe halves is usually an installation error rather than a worn part, and Whisker’s sequence is specific about the overlapping edge sitting between the two halves as a seal. Reinstall before buying.
The warranty path, before you buy
Whisker’s replacement parts page states that a robot under warranty may be eligible for a free one-time replacement of the globe liner, seal strips, motor, laser board, bonnet, or power supply, through the account rather than the shop: log in, go to My Robots, select Replacement Parts. The liner product page repeats it: under warranty, select the part free of charge; out of warranty, $70.
That sequencing matters: a $70 part bought outside the warranty flow is the most avoidable cost here, and the check takes a login. The same logic applies to a base, which the pinch detect fault guide covers.
Whisker also sells an extended warranty at $129, a three-year plan covering the unit including accidental damage with free shipping both ways. The arithmetic on whether it is worth buying sits with the rest of the running costs in our Litter-Robot cost of ownership breakdown.
Litter-Robot 4 replacement, step by step
Whisker’s published procedure requires a Phillips-head screwdriver and a flathead screwdriver or panel removal tool. The short version, with the parts people get wrong called out.
Removal:
- Home/Ready, power off, then unplug. Unplugging rather than switching off is Whisker’s instruction.
- Open the bonnet by pressing the latches on both sides, then lift and rotate it back.
- Remove the fence from the bezel if fitted.
- Lift the globe off the base by the black handle and set it on the floor.
- Remove the liner clip at the lower front edge with the flathead. Note how the two fingers on each side sit inside the globe.
- Remove the four screws holding the black gear track to the back of the globe.
- Remove the ten screws holding the upper and lower halves together, and lift the upper half away.
- Remove the liner, turn it over, and take out the liner weight and, if fitted, the weight retainer. Set both aside. Do not discard.
Installation:
- Turn the new liner over, insert the round weight in the centre location, and fold the outer lip over the weight edge.
- If a retainer is supplied, lay it on the weight and insert its three tabs into the matching slots. A liner with three slots is an updated design and the retainer is required on it.
- Place the liner into the lower half and work around the perimeter, pressing it over the outer edge. At the mid-point, tuck the two centre fingers inside the globe, outside the liner.
- Lower the upper half and align it. The overlapping edge sits between the halves and acts as the seal.
- Install the ten Phillips screws, then fit the front liner clip without bending the two centre fingers.
- Lay the globe on its face, opening down, and install the gear track with the four screws.
- Set the globe on the base by the handle, handle and waste port toward the top, and confirm the large black gear engages the small white drive gear.
- Close the bonnet, press the centre tab, refit the fence, plug in, power on.
Three steps are where installs go wrong. Step 8: the weight is not in the new liner box, and a liner without it has no clump-separation bias. Step 12: an edge folded under instead of over leaks litter into the seam and eventually jams the gear track. Step 13: the clip’s two centre fingers are thin, and bending them means the liner is not held where a cat’s paws dig hardest.
How the 5 and 5 Pro differ
The Litter-Robot 5 and 5 Pro use a shorter teardown with fewer screws, and Whisker’s guide for them is a separate document.
Two differences matter. The 5 uses seven screws on the globe cap instead of ten across two halves, and it adds a key at the rear that can fall out when the globe is lifted: hold it in place while lowering the globe back, and note that removing the bonnet is not necessary but may make the job easier.
The rest of the sequence is identical. Whisker does not list a 5 globe liner at a capturable URL, so that part’s price is unverified; the warranty route is the same account path.
The liner weight
The weight is a small round metal disc, and it is the part that makes the liner work.
Mechanically, the weight holds the centre of the liner low while the drum rotates, so the rubber is stretched slightly rather than rotating as a rigid sheet, and a clump sitting on it cracks free at the point where the surface flexes.
That is why a liner installed without a weight behaves like a different product, and why surface rust is safe: the weight’s function is mass, not finish. If it is lost, the route is a support ticket, since Whisker does not list the weight as a standalone item.
Which faults a worn liner causes
A worn liner produces no error code, only symptoms diagnosed as something else, which is where owners spend money on the wrong part.
Clumps that stick and then break loose mid-cycle land in the waste port as a lump rather than crumbs, one of the documented triggers for a pinch detect fault, and our pinch detect guide works that order: if the ping-pong light returns after a clean port and clicking pinch bars, the liner belongs on the list before a base.
A liner lifted at the fold can hang into the port path, the same fault from a different cause: Whisker names loose drawer liners and loose carbon filter covers as soft obstructions, and a peeled globe liner edge behaves identically.
A liner not seated between the globe halves lets litter into the seam, and litter in the seam is grit in the gear track, which presents as a grinding cycle or incomplete rotation and reads like a motor fault when it is not.
Odour returning within a day of a deep clean is the subtlest signal: rubber is not non-porous the way stainless is, and urine penetrates a degraded surface, so no cleaning reaches what has soaked in.
The cat sensor fault is a separate path and rarely traces to the liner, but the two get confused because both stop the machine: our cat sensor fault guide covers the red flashing pattern and weight calibration, the place to start if the machine refuses to cycle at all.
Third-party liners
Whisker describes the official liner as extra durable and does not publish a rubber specification; no third-party liner was captured with published material data.
The risk is higher than on a bag because the liner is structural: it seals the two globe halves, carries the weight, and takes the load of a cat digging. A liner of different gauge or rubber either fails to seal at the overlap, letting litter into the seam, or fails to flex, bringing back the sticking-clump problem the part exists to solve. Holes a millimetre off mean the liner bunches at one point and stretches at another.
The honest argument for a third-party liner is price on an out-of-warranty machine that is otherwise fine, which is a calculation with unknowns on both sides. Do not substitute a waste drawer bag: no weight, no bond, no seal.
Replacement interval and annual cost
Whisker publishes no replacement interval for the globe liner, but a cost frame can still be built. The part is $70 on the Litter-Robot 4: one replacement in five years adds $14 a year, two add $28. Against a $699 machine and a litter bill in the hundreds annually, the liner is a minor line item.
| Item | Price | Interval | Annual cost |
|---|---|---|---|
| Litter-Robot 4 globe liner | $70 | Not published by Whisker | $14 if replaced once in 5 years |
| Waste drawer liners, 25-pack | $25 list, $17.50 autoship | About 25 empties | Depends on cats: see below |
| Waste drawer liners, 50-pack | $35 list, $24.50 autoship | About 50 empties | Best unit price of the three packs |
| Carbon filters | [DATA NOT VERIFIED: price not captured on the product page] | Whisker does not publish a fixed interval | [DATA NOT VERIFIED] |
| WhiskerCare extended warranty | $129 | 3 years | $43 |
The drawer liner rows connect to the emptying cadence: Whisker’s maintenance page puts a single cat at about one empty per week and two average cats at twice a week, which means a 50-pack lasts roughly a year for one cat and six months for two.
For the fuller picture of what the machine costs to run, including litter and the drawer bags, our automatic litter box consumables breakdown does the same arithmetic for the whole category, and the Litter-Robot cost of ownership breakdown covers the machine-specific version.
Our verdict
Check the warranty before buying anything. A globe liner is free once under warranty through the account, and $70 outside it, and the difference is one login.
Replace on behaviour, not on a calendar, because Whisker publishes no interval: the clearest signal is clumps sticking to a liner that has just been cleaned, followed by tackiness and odour that returns within a day. Rust on the weight is not a signal.
Reinstall before replacing if litter is escaping between the globe halves: that is usually the overlapping edge folded wrong rather than a worn part.
Keep the weight. It is the mechanism, not an accessory, and the new liner arrives without one.
If a fault appears after the swap, work the documented fault path rather than assuming the new part is at fault: a pinch detect light after a liner change is more often a soft obstruction in the port than a bad install, and the pinch detect guide starts with the free checks.
How we researched this
- The replacement procedure, tool list, screw counts, and the liner weight warning come from Whisker’s published installation guides for the Litter-Robot 4 and the Litter-Robot 5 and 5 Pro, fetched on 2026-10-29 through a US egress with an en-US language header.
- The $70 price is the figure shown on Whisker’s own globe liner product page on that date. The warranty path and the list of parts eligible for one-time free replacement are from Whisker’s replacement parts page.
- Drawer liner pack prices and the product’s own description are from Whisker’s waste drawer liner page. The emptying cadence is from Whisker’s ongoing maintenance page, not an estimate.
- The mechanism the liner weight performs is Whisker’s own explanation in its installation guide, quoted rather than inferred.
- Fault interactions are cross-referenced to Whisker’s published pinch detect and cat sensor articles. Where a part price could not be captured, the row is marked rather than estimated.
- This is a research-based review. Specifications come from manufacturer documentation, with owner-reported wear patterns aggregated from public product reviews.
See the full methodology page for how sourcing and affiliations are handled.
Sources
Fetched on 2026-10-29 through a US egress with an en-US language header:
- https://www.litter-robot.com/litter-robot-4-globe-liner.html
- https://www.litter-robot.com/support/article/litter-robot-4-globe-liner-installation-guide/
- https://www.litter-robot.com/support/article/litter-robot-5-globe-liner-installation-guide/
- https://www.litter-robot.com/support/article/litter-robot-4-replacement-parts/
- https://www.litter-robot.com/support/article/litter-robot-4-ongoing-maintenance/
- https://www.litter-robot.com/support/article/litter-robot-4-deep-cleaning/
- https://www.litter-robot.com/support/article/litter-robot-4-yellow-ping-pong-pinch-detect/
- https://www.litter-robot.com/litter-robot-waste-drawer-liners.html
- https://www.litter-robot.com/litter-robot-4.html