ROBOFAULTS
ECOVACS·FAULT 3 BEEPS WARN

ECOVACS Error 3 beeps — Drop sensors or dust bin fault

Severity: Warning — robot refuses to run until its sensors read clean or the bin sits right N79/N79S/N79W600/601/661
Last verified: 2026-07-07 Tools: dry cloth Time: ~10 min Difficulty: easy

DIRECT ANSWER

Three beeps split by model: on the N79 family, flashing red = anti-drop (cliff) sensor malfunction, solid red = dust bin fault — empty it; on DEEBOT 600/601/661 they mean the dust bin isn't seated properly.
#meaning · #causes · #fix · #parts — link straight to any section

COMMON CAUSES · RANKED

1

N79, flashing red — dust on the anti-drop sensors MOST COMMON

The official fix is cleaning the anti-drop sensors as described in the manual's maintenance section — dust makes them read a cliff everywhere.

2

N79, solid red — dust bin full

The manual's solid-red variant maps three beeps to the dust bin — emptying it per the maintenance section clears the alarm.

3

DEEBOT 600/601 — bin not clicked in

The official instruction is to make sure the dust bin is installed — and if it is, to take it out and put it back in properly.

4

Debris on the bin contacts UNCOMMON

Fine dust on the bin's seat or contacts keeps a correctly-filled bin reading as missing — wipe both before reseating.

HOW TO FIX IT

No battery or electrical work involved in this fix.

Match the alarm to your model

N79 family — flashing red means sensors, solid red means the bin. 600/601/661 — reseat the bin first.

Wipe the anti-drop sensors

Power off, turn the robot over, and wipe every sensor window on the underside with a clean dry cloth.

Empty and reseat the dust bin

Remove the bin, empty it, wipe its seat and contacts, and push it back in until it sits flush.

Check the filters while the bin is out

A clogged sponge or high-efficiency filter chokes airflow — knock them clean or replace them, and dry fully if washed.

Restart the clean

Run a short clean; if three beeps persist with clean sensors and a seated bin, contact ECOVACS support.

COMPATIBLE PARTS

As an Amazon Associate, RoboFaults earns from qualifying purchases. Prices are shown on the retailer's site.

Filter set (sponge + high-efficiency) — N79 family & 500/600 series

Filter set (sponge + high-efficiency) — N79 family & 500/600 series

N79N79SN79W500600601661

The dust bin holds a sponge filter plus a pleated high-efficiency filter. Per the official manual, pat the high-efficiency filter clean and never rinse it; the sponge filter and bin can go under running water. Replace the pair every 3-6 months.

Compatibility and replacement details → Check price on Amazon ↗

Sources

Verification

OFFICIAL SOURCE

Last verified: 2026-07-07 · How we verify a fault code

Corrections

Spotted an error? Report a correction — fixes ship within 48h and are logged on this page.