When your Tuttnauer autoclave starts displaying error codes, your first reaction is probably panic. His autoclave is one of the most important pieces of equipment he has and without it he cannot sterilize his tools. And if he can’t sterilize his tools, he’s out of business. But do not worry. A low temperature error code is not a cause for alarm. And you can probably fix the problem yourself.
A low temperature error code is displayed if the temperature in the chamber begins to drop. If the temperature drops more than 4.5ºF, the sensor will automatically abort the cycle and the cycle failure indicator lights will also flash. All those flashing lights make the situation look like the plane is about to crash and everyone needs to grab a parachute. But it’s just a little turbulence. hold on. You can fix it.
First, check the water level in the chamber. If there is not enough water in the chamber then there will not be enough steam and steam is needed to generate the heat that sterilizes your tools. Here are some things to check:
- Check the water level in the reservoir to make sure it is full
- Make sure your autoclave is properly leveled
- Check that the water detection electrode is not dirty or it may be shorted
- Make sure the water pump is not clogged.
- Check for clogged water lines
- Make sure the air outlet valve is working properly
Then, if the water level in the chamber is okay, check your cycle time. If the cycle was set for too long a period of time, the water in the chamber may have evaporated and therefore the chamber is dry. This often happens, especially in autoclaves with manually set timers.
If it’s not a timer problem, then you need to check the safety thermostat. It may be faulty. When the safety thermostat opens, it automatically turns off the heating elements, as a safety measure. On Tuttnauer T935N5 and T935N6 autoclaves the safety thermostat has been known to open prematurely.
You should never try to recalibrate the safety thermostat. It was factory calibrated and must be replaced with another factory calibrated thermostat. With that said, you can replace that thermostat yourself.
Unplug your autoclave first and then remove the wires from the thermostat terminals. You’ll want to label them so you can easily reconnect the replacement. Next, remove the screws or unscrew the lock that holds the safety thermostat to the mounting bracket. Loosen the screws that hold the thermostat to the heating element and remove the probe. Be careful when unwinding the tube that connects the probe to the contact body. It’s full of fluid and if you puncture it, you’ll need to replace it too.
Now simply mount the new thermostat and run a test cycle to make sure everything is working properly again.
As you can see, there really is no need to panic when your Tuttnauer autoclave displays a low temperature error code. It is easy to fix the problem yourself. In fact, it’s just as easy to fix almost any problem you have with your autoclave. So don’t let all those flashing lights scare you. Take a wrench and fix it yourself.