Why has my dental chair stopped moving?

A dental chair that suddenly stops moving is most often a safety switch that has been triggered by a cover that has shifted or stuck, not a mechanical fault. The other common cause is a jammed foot control. If the chair has no power at all, check the main switch and wall isolator first. Clinic staff can usually clear all three in a couple of minutes.

Is the chair actually switched on?

If the screen is blank and the operating light is off, this is not a safety switch. The chair has lost power. Check the main switch on the chair and the isolator on the wall. If both are on and the chair is still dead, it needs a technician.

If the chair is powered up but will not move, continue below.

1. Has a safety switch been triggered?

Almost every dental chair has safety switches built in. They stop the chair moving if something is in the way, to protect patients, staff and the chair itself. When a chair stops for no obvious reason, it is usually one of these switches. Most of the time the switch itself is fine. A cover has shifted or stuck and is pressing on the switch, so the chair thinks something is in the way.

The two most common culprits are the backrest cover and the base plate cover, so start there.

On most Dentsply Sirona chairs, the screen will tell you which safety switch has tripped, which points you straight to the right cover.

Quick fix: Work around the chair and push up firmly, but gently, on each of the lower covers one at a time. Do not force anything. You are checking whether each cover moves freely and sits back into place, or whether it feels stuck or out of line. A stuck cover is almost always the problem. Once it is freed, the chair should move again.

2. Is the foot control stuck?

If the foot pedal is jammed, or something is resting on it and holding it down, the chair will not move. Check that the pedal moves freely and that nothing is pressing on it. Look underneath it as well, because cables and dropped items end up there.

How do I stop this happening again?

Most tripped safety switches come from covers being knocked by feet, mobile carts or the operator stool. Keep the floor around the chair base clear and have staff tell you if a cover looks loose or misaligned, so it can be reseated before it stops a session.

Still stuck?

If the chair has power, you have checked the covers and the foot control, and it still will not move, call Universal Dental Solutions on (02) 8313 0559. Tell us what the screen says, if anything. A technician can usually talk you through finding the exact cover over the phone, and if it does need a visit, we will arrive knowing where the problem is.

Frequently asked questions

Why does my dental chair only move in one direction?

This is almost always a safety switch. A tripped switch blocks movement in the direction that would cause a collision but often allows the opposite direction. Check the covers as above.

Where are the safety switches on a dental chair?

It varies by model, but the most common locations are under the backrest, under the base plate and on the spittoon or cuspidor. Your chair's manual will show the exact positions.

Can I reset the safety switch on my dental chair?

There is usually nothing to reset. Once the cover that is pressing on the switch is freed, the chair moves again. If it does not, the switch itself may have failed and needs a technician.

Is a stuck dental chair an emergency?

If a patient is in the chair and it is stuck in a position they cannot safely get out of, call us straight away. Otherwise, work through the checks above first.