SHARK·FAULT ERR 21 WARN

Shark Error 21 — Boot-up error

Q: Shark Error 21 — Boot-up error

Error 21 means the robot hit an error while booting. The official fix is a power-cycle: turn the robot off, wait, and turn it back on. A repeating boot error is a service case.

Severity: Warning — robot's software failed to start — a power-cycle usually clears it IQEZAIAI UltraMatrixPowerDetect

Last verified: 2026-07-06 Tools: none Time: ~5 min Difficulty: easy

DIRECT ANSWER

Error 21 means the robot hit an error while booting. The official fix is a power-cycle: turn the robot off, wait, and turn it back on. A repeating boot error is a service case.

#meaning · #causes · #fix · #models — link straight to any section

COMMON CAUSES · RANKED

One-off software glitch at startup MOST COMMON

The boot sequence occasionally hangs; the owner's guide fix is simply to turn the power off and back on.

Interrupted start on a low battery

Waking with a nearly flat battery can abort the boot — charge the robot fully before retrying.

Persistent firmware or board fault RARE

If every start ends in Error 21, the firmware or main board needs attention from Shark support.

HOW TO FIX IT

No battery or electrical work involved in this fix.

Power the robot off

Take it off the dock and hold the POWER button for 3 seconds until it shuts down.

Wait, then power back on

Leave it off for about a minute, then set it on the dock to power it back on.

Contact support if it repeats

A boot error that returns on every startup won't be fixed by cleaning — quote your model and the code to Shark support.

Did this fix your robot?

No reports yet for this fix — be the first.

MODELS AFFECTED

Model	Status	Firmware	Parts	Verified
Shark IQ Robot RV1001	active	—	Parts →	2026-07-06 · Source
Shark IQ Robot Self-Empty XL RV1001AE	active	—	Parts →	2026-07-06 · Source
Shark EZ Robot Self-Empty AV911S	active	—	Parts →	2026-07-06 · Source
Shark AI Robot RV2001 / AV2001	active	—	Parts →	2026-07-06 · Source
Shark AI Ultra Robot RV2502AE	active	—	Parts →	2026-07-06 · Source
Shark Matrix Robot RV2310	active	—	Parts →	2026-07-06 · Source
Shark Matrix Plus 2-in-1 RV2610WA	active	—	Parts →	2026-07-06 · Source
Shark PowerDetect NeverTouch RV2820ZE	active	—	—	2026-07-06 · Source
Shark PowerDetect ThermaCharged RV2910XE	active	—	—	2026-07-06 · Source

Models resolved from the series chips above. Support status comes from our EOL library; rows link to the matching parts and firmware pages.

Sources

Verification

OFFICIAL SOURCE COMMUNITY-VERIFIED

Last verified: 2026-07-06 · How we verify a fault code

Corrections

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