Why does my CATLINK keep showing a cat detected error when no cat is inside?

The entry infrared sensor lenses have built up a film of dried clay dust and moisture. The film blocks the light beam so the sensor permanently reads as obstructed. Cleaning the lenses with 99% isopropyl alcohol on a lint-free swab resolves it.

Why does my CATLINK say the drawer is full when I just emptied it?

The waste drawer uses an infrared beam to detect fill level. If the plastic bag liner has creases or folds that protrude upward into the drawer opening, they reflect the beam and the unit reads it as waste blocking the sensor. Replacing the bag and pressing it flat against the drawer walls fixes it.

How often should I clean the CATLINK IR sensors?

In high-use households, a quick wipe of the entry sensors with a dry cotton swab every 2–4 weeks prevents the dust film from building up to the point where it causes false lockouts. A deeper isopropyl alcohol clean is needed once a full lockout occurs.

TB-CTL-001 · Hardware Fix · 22 May 2026

CATLINK litter box: unit thinks a cat is always inside, or drawer is always full

Both errors are sensor problems, not mechanical ones. A thin film of dried clay dust on the entry sensor causes a permanent false detection, and a loosely fitted waste bag creates a reflection the drawer sensor mistakes for waste.

Device CATLINK Self Cleaning

Impact Cycles halted

Fix time 20 minutes

Tools needed Cotton swabs, isopropyl alcohol

01 — Why the sensors give false readings
02 — Fix checklist
03 — Replacement hardware
04 — Advanced: cloud connection dropping

01 — Why the sensors give false readings

Two completely independent sensors can each cause the unit to stop all cycles — and both have simple physical explanations.

Dust and moisture coat the entry sensor — it reads as always occupied

The entry infrared sensor continuously scans for an approaching animal. In busy households, warm moist air from the litter mixes with fine clay dust and rises toward the sensor lenses above the opening. The moisture makes the dust stick; when it dries, it leaves a hard, opaque mineral film on the sensor aperture. The infrared beam can no longer get through — the sensor permanently reads "blocked," and the firmware treats it as a cat standing at the entry. The unit freezes and will not run any cycle regardless of how many times you restart it.

A loose or wrinkled waste bag reflects the drawer sensor beam

The waste drawer uses a horizontal infrared beam to tell when waste reaches the fill line. If the plastic bag lining the drawer has creases or folds sticking up from the sides, the glossy plastic acts as a reflective surface. The reflected beam bounces away from the receiver, and the firmware interprets the missing signal as waste blocking the sensor path — exactly the same reading it gets when the drawer is genuinely full. The unit sends a false "Drawer Full" alert and stops all automated cycles until you acknowledge it.

02 — Fix checklist

Part A cleans the entry sensor lenses. Part B corrects the waste drawer liner. The reset in Step 6 clears both errors from the firmware at once.

Progress 0 / 6

Part A — Clean the entry sensor

Unplug and remove the globe housing

Press and hold the power button to switch the unit off, then unplug it from the wall. Lift the outer globe straight up off the base — it sits in tracks and lifts free without tools. Set it aside on a surface you can clean later.

Clean the entry sensor lenses with isopropyl alcohol

Look directly above the entry opening in the base unit. You'll see two small circular recessed ports — the infrared emitter and receiver. Soak a lint-free cotton swab in 99% isopropyl alcohol and gently scrub inside each aperture in a circular motion. The dried mineral film takes a few seconds of firm scrubbing to lift. Use a second dry swab to absorb the alcohol and wipe the lens clean. Do not use water.

Part B — Fix the waste drawer

Replace the waste bag with a fresh one

Pull out the waste drawer. Remove the existing liner completely and discard it — even if it's not full. Any creases or folds in the old bag may already be causing the false reading. Fit a fresh bag: hold one end against the back of the drawer and drape the rest over the front rim.

Pull the bag tight and press the bottom flat

Working around the perimeter, pull the bag edges firmly over the plastic rim so the sides are smooth and taut. Press the bottom of the bag firmly down against the floor of the drawer. There should be no loose plastic standing up inside the drawer cavity — any upright fold can reflect the level sensor beam. Run your hand along all four inner walls to confirm.

Wipe the chute sensor windows

Before pushing the drawer in, look at the left and right inner walls of the waste chute — there are small clear plastic windows protecting the drawer level sensors. Wipe each window with a dry anti-static cloth to clear any litter dust that has settled on them.

Reassemble, reset, and run a test cycle

Push the drawer in firmly. Re-seat the globe onto the base. Plug the power cord back in. Press and hold the Manual/Reset button for 6 seconds — the unit will beep and cycle through its indicator lights, clearing both sensor error states. Open the app and trigger a manual cycle to confirm the drum completes a full rotation without stopping.

If the cat-detected error returns within a few days, the sensor lens may need a second clean — some mineral deposits require two passes to fully remove.

03 — Replacement hardware

If the entry sensor keeps triggering false detections after thorough cleaning, the sensor itself may have physical damage or corrosion that can't be cleared with isopropyl alcohol.

Replacement option

CATLINK self-cleaning litter box

A replacement unit has fresh, uncorroded sensor apertures. If you switch, consider setting up a monthly dry-swab cleaning routine to prevent the dust film from building up again.

Check price for CATLINK self-cleaning litter box

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04 — Advanced: cloud connection dropping

For units that show online in the app but don't respond to commands, or that drop offline after long idle periods.

Fixing CATLINK cloud dropouts on managed or firewalled networks

The CATLINK holds a persistent connection to its cloud server to stream health data (weight, visit duration, litter usage). It communicates over TCP port 8883 (secure MQTT) and port 443 (HTTPS). If either port is blocked by a router firewall or enterprise security gateway, the data connection silently drops. The unit still shows a Wi-Fi icon but can't receive commands or send health updates.

Fix: in your router or firewall settings, create an outbound allow rule for the CATLINK's IP address covering TCP port 8883 and TCP port 443. If your router has "deep packet inspection" (DPI) enabled on IoT traffic, disable it for these ports — DPI can strip the secure headers and cause the connection to be refused.

On networks with aggressive NAT timeout settings (where idle TCP connections are closed after 5 minutes), the CATLINK's long periods of standby between visits cause the connection to be silently killed. Set the TCP established connection timeout for your IoT VLAN to at least 3600 seconds (one hour) to prevent mid-idle disconnections.