ERROR CODE C983: HEATUP

Free Autoclave Troubleshooting Guides



Midmark M9 & M11 Error Code C983 (HEATUP)


The Error Code "C983 (HEATUP)" means the High-Limit Thermostat is open. This is normally due to lack of water inside the chamber

Before proceeding: Allow unit to cool for 30 minutes. Unplug unit for 60 seconds, then plug unit into a dedicated, properly rated circuit

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 C983 (HEATUP) 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 Mode

If, after you select a cycle and push start, the autoclave does not display filling, but goes directly into the heat up mode, then this is what you need to look for

Display/Symptom Cause What to Check Solution
C983 (HEATUP):
HI-LIMIT OPEN
UNPLUG / REPLUG UNIT

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

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 electrical 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 C983 (HEATUP) Error Code, then this is what you need to look for:

Display/Symptom Cause What to Check Solution
C983 (HEATUP):
HI-LIMIT OPEN
UNPLUG / REPLUG UNIT

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

Pressure leaking from chamber. Check for pressure leaks. Click Here To See "How To Find Pressure Leaks" Repair or replace malfunctioning component
High-limit thermostat malfunctioning If error code does not reset... Perform High Limit Thermostat Continuity Test Replace High Limit Thermostat(s)

Click Here For M9 High Limit Thermostat(s) or

Click Here for the M11 High Limit Thermostat(s)

Loose or damaged wire connection(s) Check wire connections at these locations: Wires From High-limit Thermostat Terminals to J5 on main PC board Secure, repair or replace loose or damaged connections
Sterilizer is not level Be sure support surface (countertop) is level Place sterilizer on a level support surface (make sure the counter top where the area the autoclave will be setting is level)

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