Why is water leaking from under my dentist element?
Water dripping from under the dentist table is almost always worn O-rings on the turbine coupling. Four causes to check, in order, before you call a technician.
Water leaking from under the dentist element is almost always caused by missing or worn O-rings on the high-speed turbine coupling. Water gets into the exhaust air line and comes out of the turbine vent. Check the O-rings first, then the coupling, the handpiece and the hose, in that order. Most clinics can find and fix the cause in about ten minutes.
Where is the water coming from?
Every turbine hose has a vent for the exhaust air. On a Dentsply Sirona chair, and most other brands, the vent is on the hose where it plugs into the chair under the dentist table. On an A-dec chair, it is on the back of the dentist element. If water gets into the air line, it comes out of that vent. The vent itself is not faulty. It is showing you that water is getting in somewhere upstream.
What are the most common causes of a turbine water leak?
There are four. Check them in this order, starting with the most common.
1. Are the O-rings on the coupling missing or worn?
This is the most common cause. If an O-ring is missing, water crosses into the air line. Look closely at the O-rings on the high-speed coupling. Sometimes one is gone altogether. More often it is worn, so look under good light for small cuts and nicks in the rubber.
Fix: Replace the O-rings.
2. Is the coupling faulty?
If the O-rings look fine, the coupling itself may be the problem. Swap it with the coupling from another chair. If the leak moves to the other chair, the coupling is the cause.
Fix: Order a new coupling.
3. Is the handpiece faulty?
Also common, and usually the one that comes and goes. If the leak happens with one handpiece but not another, that handpiece is the problem. This is particularly common with NSK-style handpieces, because their O-rings are on the handpiece rather than the coupling.
Fix: Send the handpiece for repair or replace it. For NSK-style handpieces, try new O-rings first.
4. Is the hose faulty?
The least common cause. It happens when the water line inside the hose bursts. To test it, turn the water off at the coupling's water adjustment, then run the hose with the chair's water on and no handpiece connected. If it still leaks, the hose is faulty.
Fix: Replace the hose.
How do I check the leak is actually fixed?
Do not skip this step. Water left in the line can make a repaired chair look like it is still leaking.
- Connect a handpiece and turn the water off at the coupling.
- Run the hose until no more water drips from the vent. This clears water already sitting in the line.
- Once it has been dry for at least 10 seconds, wipe around the connector with paper towel until it is completely dry.
- Turn the water back on and run the hose for 30 to 60 seconds.
If it stays dry, it is fixed. If it leaks again, move to the next cause on the list.
How do I stop this happening again?
Check the O-rings on each coupling every time you change handpieces. A worn O-ring costs a few dollars and takes seconds to replace. A leak left running can damage the coupling and the hose.
Still leaking?
If you have checked all four causes and the chair is still dripping, the fault needs a technician. Call Universal Dental Solutions on (02) 8313 0559. Because you have already done the checks, we will know what to bring and get you running again faster.
Frequently asked questions
Can clinic staff replace turbine O-rings themselves?
Yes. O-rings on the coupling are a consumable part designed to be changed by the user. Use the correct size for your coupling model and lubricate them lightly if the manufacturer recommends it.
Why does my turbine leak water only sometimes?
An intermittent leak usually means the fault is in one specific handpiece rather than the chair. Note which handpiece is on when it leaks.
Is a leaking turbine vent dangerous?
No, but it should not be ignored. Water in the drive air line can shorten the life of the coupling, the hose and the handpiece bearings.
How much does it cost to fix a turbine water leak?
If it is the O-rings, a few dollars. A replacement coupling or hose costs more, but is still far less than a callout for a fault you could have found yourself.