By 
When your Tuttnauer autoclave starts flashing error codes, your first reaction is probably panic. Your autoclave is one of the most important equipment you have and without it you cannot sterilize your tools. And if you can’t sterilize your tools, you’ll be ruined. However, don’t worry. A low temperature error code is not a cause for alarm. And you can probably repair 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 Fail 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 create the heat that sterilizes your tools. Here are a few things to check:
- Check the water level in the reservoir to make sure it is full
- Make sure your autoclave is properly leveled
- Check if the water sensing electrode is dirty or may be shorted.
- Make sure the water pump is not clogged
- Look for clogged water lines
- Make sure the air outlet valve is working properly
Then if the water level in the chamber is fine, check your cycle time. If the cycle was set for too long a period of time, the water in the chamber may have boiled and that is why the chamber is dry. This happens often, especially in autoclaves with manually set timers.
If it’s not a timer issue, 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 the Tuttnauer T935N5 and T935N6 autoclaves, the safety thermostat is known to open prematurely.
You should never attempt to recalibrate the safety thermostat. It was factory calibrated and should 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 secures the safety thermostat to the mounting bracket. Loosen the screws that hold the thermostat to the heating element and remove the probe. Take care when unwinding the tubing 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 repair the problem yourself. In fact, it’s just as easy to fix any problem you have with your autoclave. So don’t let all those flashing lights scare you off. Take a wrench and fix it yourself.