Midmark M9 & M11 Error Code C533: HEATUP MODE

When is the error code appearing?

The first step in determining the problem and it's solution is to take note of when the Error Code C533: HEATUP MODE is appearing. Once you know when the error code is appearing, scroll down & locate the proper chart for solutions

If The Autoclave Skips The FILL Cycle

Display/Symptom Cause What to Check Solution

Sterilization Mode not reached after 25 minutes.
The Base Tray Plate or the Tracy Rack is not installed properly Inspect Base Tray Plate and Tray Rack for proper installation. (Angled end of Base Tray Plate must be toward the back of the chamber) Install Base Tray Plate and Tray Rack properly. Unplug the autoclave for 60 seconds before plugging back in
Water Level Sensor Not Functioning Properly Check the Water Level Sensor Disc to see if it is damp or wet Dry Water Level Sensor Disc with a Lint Free Cloth and try another cycle
While there is an electical test you an perform to verify the water level sensor is malfunctioning, there is a more simple & direct way to test it Remove the Base Tray Plate & Tray Rack from the autoclave. Pour Distilled Water into the chamber until it touches the water level sensor & start another cycle. If it successfully completes the cycle, then you know the Water Level Sensor is bad & needs to be replaced

If The Autoclave Completes The Fill Cycle

If after selecting a cycle, the display reads FILLING and then advances to the heat up mode prior to giving you the C533: HEATUP MODE Error Code, then this is what you need to look for:

Display/Symptom Cause What to Check Solution

High-limit thermostat opened for at least 0.25 seconds during POWER UP mode

Pressure leaking from chamber. Check for pressure leaks. Click Here To See "How To Find Pressure Leaks" Repair or replace malfunctioning component
Temperature Sensor malfunctioning Be sure there is nothing touching the temperature sensor. (Example: trays, pouches, cassettes, etc.) Reposition items so nothing touches the temperature sensor
Check the temperature sensor probe for corrosion or residue Clean the temperature sensor with Mid-Clean™ and distilled water
Perform Temperature Sensor Testing Follow instructions in test procedures
Place a Maximum Registering Thermometer inside the autoclave chamber. Click Here to get one (Part #RPT113-3699)

Run the "Heating Element Test" and compare the temperature readings

Refer to: Service Diagnostics (I/O Test)
If STEAM temperature reading is not in line with temperature probe reading, replace temperature sensor

Click Here for the Midmark M9 Temperature Sensor Part #MIS121-4037

Click Here for the Midmark M9 Temperature Sensor Part #MIS121-4038
Sterilizer is not level Check surface where autoclave is located to make sure it is level Level with From Leveling Feet, or move the autoclave to a level surface
Heating element malfunctioning Test the Heating Element Replace The Heating Element if it fails the test

Click Here and scroll down the page for the instructions on testing the Midmark M9 autoclave

Click Here and scroll down the page for the instructions on testing the Midmark M11 autoclave widget logo