SIROTorque & SIRONiTi Not Working? Error Codes, Endo Problems and Step-by-Step Fixes

An "F" flashes on the display. The file stops turning. Or the SIRONiTi releases before you expected it to. When an endo setup misbehaves, it is easy to blame the wrong part, and with a SIROTorque motor system that Dentsply Sirona no longer supports, a wrong guess can be expensive.

This guide starts with the error codes Sirona built into the SIROTorque L+, then moves to the problems clinicians notice at the SIRONiTi contra-angle. Each section tells you what to check safely, and where to stop.

First Question: Is It the Motor or the Contra-Angle?

The SIROTorque L / L+ is the motor system that drives your attachment. SIRONiTi is the torque-limiting endo contra-angle on the end. If the display shows an error code, the problem is almost always in the motor system. If the display is normal but the file behaves oddly, look at the contra-angle and your settings first.

The 60-Second Triage

Read the display. Note any error code before you do anything else.
Lift your foot. Several faults clear once the foot switch is released.
Check the direction arrow. A flashing counterclockwise arrow means reverse is on.
Swap the attachment. Try another contra-angle on the same motor. If the fault stays, it lives in the motor system.
Check the SIRONiTi setting. Confirm the preselect ring matches the Torque CARD for the file in use.

SIROTorque Error Code Decoder

The SIROTorque L+ operating instructions show errors on the "Bur Speed" display, with the display illumination flashing while an error is shown.

Code	What It Means	Safe First Step	Call a Technician When
F1	Motor switched off for safety: overheating or low supply voltage	Lift foot, wait about 1 minute for F1 to clear	It keeps returning
F2	EEPROM error	None for users	Immediately
F3	Power cut while foot switch was pressed	Lift foot, secure power supply, restart	Power interruptions continue
F5	No motor connected, or motor or hose defective	Reconnect the motor properly	F5 persists after reconnecting
F11 to F14	Short-circuit protection, weak motor connection, position detection fault, lamp circuit overcurrent	Switch off, check motor, lamp and hose installation, switch on	Code reappears after the check

Problem: The Motor Stops Mid-Procedure (F1)

F1 means the unit shut the motor down to protect itself, either because it is overheating or the supply voltage is too low. Take your foot off the switch and wait about a minute until F1 disappears. If it returns often, have the motor system checked rather than working around it.

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Problem: The Motor Will Not Run (F5)

F5 tells you no motor is connected, or that the motor or motor hose is defective.

Make sure the motor is properly connected to its hose.
Look along the hose for visible damage.
If F5 stays after reconnecting, the motor or hose likely needs replacement or repair.

Problem: F3 After a Power Blip

F3 appears when the unit loses power while the foot switch is pressed, for example through a loose contact or a brief outage. Lift your foot, make sure the power supply is secure, and restart. Recurring F3 errors point to a connection or supply issue worth investigating.

Problem: The Light Is Out or Errors F11 to F14 Appear

These codes cover deeper electrical faults. F11 means the short-circuit protection has activated. F12 points to a weak electrical connection between the motherboard and the motor. F13 means the position detection in the motor is defective. F14 indicates overcurrent in the motor lamp circuit, caused by a defective lamp or motor.

Sirona's remedy for all four is the same: switch the unit off, check that the motor, lamp, and motor hose are installed properly, and switch it back on. If the code returns, contact a service engineer.

Start Your Repair

Problem: The File Turns the Wrong Way

The SIROTorque L+ has a Reverse key, and counterclockwise rotation is shown by a flashing arrow. The unit returns to clockwise whenever it is switched off and on again, but Sirona advises checking before every start that reverse has not been left on by mistake. Before using reverse on purpose, confirm the attached contra-angle and instrument are designed for it. Prophylaxis contra-angles must run clockwise only.

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Problem: SIRONiTi Releases Too Early, or Not When Expected

SIRONiTi limits torque mechanically. When the set level is reached, its gold-plated magnetic coupling releases with a retro-rotation action so the file does not jam.

Confirm the preselect ring is fully seated on the intended level, out of the five available.
Check the Torque CARD for your specific file system and file.
Make sure you have the right version: SIRONiTi and APEX are 115:1, while Air+ and Air+ APEX are 66:1.
If the release still feels inconsistent with a correct setting, stop and have the contra-angle evaluated.

Problem: The File Slips or Will Not Lock

SIRONiTi is designed for standard NiTi files with a 2.35 mm shank, held in a push-button chuck. If a file will not lock, check that it is a compatible shank and fully inserted. A file that still slips is a reason to stop using the contra-angle until it has been checked.

Problem: Apex Locator Readings Seem Unreliable

SIRONiTi APEX and Air+ APEX versions include a gold clip so many electronic apex locators can connect directly, without a separate file clamp. If readings are erratic, check the clip connection and the apex locator's own lead before suspecting the contra-angle.

User-Safe Checks, Technician Work and Stop Signals

Safe for Trained Staff

Reading and clearing F1 and F3, reconnecting the motor and hose
Checking the direction arrow, speed and gear ratio settings
Setting the SIRONiTi ring and checking Torque CARDs

Technician Only

F2, and any F11 to F14 that returns after a restart
Motor, hose, or control unit replacement
Internal contra-angle repair

Stop Using It Immediately If

The SIRONiTi does not release at a setting where it should
A file slips in the chuck
The motor runs rough, hot, or noisy
Error codes return after every restart

SIROTorque & SIRONiTi Troubleshooting FAQs

What does F1 mean on a SIROTorque L+?

The motor has been switched off for safety, due to overheating or insufficient supply voltage. Lift your foot from the switch and wait about a minute until F1 disappears.

What does F2 mean?

F2 is an EEPROM error. Sirona's remedy is to call a service engineer.

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SIROTorque & SIRONiTi Troubleshooting | Repair.Dental