Hello,

I'm troubleshooting a pressure reading discrepancy with my Tuttnauer EZ10K autoclave. Despite replacing the AJUNC 3 board, the digital display still shows pressure readings approximately 10–12 PSI lower than my manual gauge. Here’s what I’ve done so far:

• Replaced the AJUNC 3 board.

• Performed a zero adjustment using test points (TP1–TP4). Voltage at TP1–TP4 is 0.5V at zero pressure, which is as expected.

• The digital display shows zero pressure when the system is at zero, but the readings are still off by about 10–12 PSI at higher pressures.

• I tested the pressure at 30 PSI:

  • Manual gauge: 30 PSI, approx. 1.5V

  • Digital display: 18 PSI, approx. 1.5V

The system appears to be reaching the correct temperature and pressure in the chamber (around 30 PSI at 273°F, based on the manual gauge), but the pressure readings remain off.

My question is: Does this discrepancy indicate an issue with the calibration or could it be related to another component, such as the digital board or wiring? I’m particularly concerned about the offset in the pressure readings between the manual gauge and the digital display.

Any suggestions or advice on how to proceed would be greatly appreciated!

Thank you for your help!

Equipment: Tuttnauer EZ10K

Our EZ10K is set for 121C, 15 min, 00 dry time.  From a cold start it reaches temperature in good time (13-14 minutes), and maintains pretty steady temperature and pressure for the first 11-12 minutes.  It then begins losing pressure, and temperature along with it.  With 2 minutes left it aborts, giving a LOW TEMP message and failure on the printout.

I verified it is putting 600 mL of water in the chamber.  There are no apparent leaks anywhere.  The water enters the chamber properly when starting a cycle, and it all goes back to the reservoir at the end.  

We replaced the water level sensor today and raised the front feet.  It still cannot complete a cycle.

Any advice on settings or parts that might help?  

I have found a screw and spring beside my sterilizer. I have also found that a screw is missing in the door of the sterilizer. If you're looking at the inside of the open door it ison the upper right side. I am wondering what order the screw and spring goes on. Is the spring between the plastic and the metal of the door and then the screw goes through first the metal of the door the spring and then the plastic of the door - or- does the spring go over the screw and into the metal of the door and into the plastic of the door. When I first put the screw in it was really tight. I don't want to break anything.