Article about daily and weekly maintenance on a Midmark M9 or Midmark M11 sterilizer autoclave.

Midmark Autoclave maintenance – M11 and M9 Leave a comment

This post was originally published on 6-13-18 and updated on 3-8-19

How often do I need to perform maintenance?

There are actually daily, weekly, and yearly checks that need to be done for proper Midmark autoclave maintenance. This is an overview of the daily and weekly portions of that schedule. Always refer to the appropriate technical documentation for the complete list of instructions, safety alerts, and sequence of procedures before conducting any service or maintenance operations.

Does maintenance really matter?

It matters so much even the machine will help you remember. To assure proper operation and maximum sterilization life, the Midmark M9 and Midmark M11 provide the operator with maintenance reminders on the display screen. The display removes the reminders once the cycle has started. Follow the recommended periodic maintenance schedule and your Midmark autoclave will provide many years of trouble-free service. Recommended maintenance is easy to do and takes very little time. If you don’t follow the maintenance schedules mineral deposits and corrosion can build up on the internal components, resulting in operational problems, downtime, and service fees.

A very simple yet important tip

Prevent many problems by ensuring that only distilled water, not tap water, is used in your autoclave. Since the autoclave operates with high water temperatures, any minerals dissolved in the water will form mineral deposits. This can prevent valves from opening or closing properly. It can also lead to corrosion in the chamber and tubing.

 Daily maintenance tasks

Wipe down the exterior of the autoclave every day. Use only quaternary disinfectants to disinfect the unit. Do not use alcohol or bleach-based cleaners. Inspect the door gasket and door dam gasket for damage. When the inspection is complete, wipe with a damp cloth. If the autoclave processes instruments that have been lubricated or dipped in ultrasonic cleaners, the autoclave must be drained and refilled with distilled water every day. This prevents other items from being contaminated with the residue from these fluids. It also prevents excessive residue build up from damaging the unit seals.

Weekly maintenance tasks

Every seven days, the autoclave will automatically display the “perform weekly maintenance” message. Midmark autoclave maintenance (weekly) consists of two operations: Changing the water in the unit and cleaning.

 How to remove the water and clean the Midmark M9 or Midmark M11

After disconnecting the upper portion of the water level indicator, bend it downward and let the reservoir drain in a suitable container, a bucket for example. Remove the trays and rack from the autoclave. To remove the tray rack, use a screwdriver and pry the plate up while pulling the tray rack and plate out of the chamber. After removing the trays and rack from the autoclave, clean the trays in the inside of the chamber with distilled water and speed clean or a mild soap. Never use bleaching agents or abrasives when cleaning because they can damage the metal services of the autoclave chamber. This includes steel wool, scouring powder, bleach, or wire brushes.

Getting the Midmark M9 or Midmark M11 ready for service

After all the cleaning it is time to get your unit ready to go back into service. To install the tray rack and plate back in the unit, insert the tray rack into the tray plate. Press down on the tray rack while sliding it into the chamber. Refill the reservoir with distilled water until the water level indicator is in the green area. The “perform weekly maintenance” message will go away during your next sterilization cycle.

For more detailed information about midmark autoclave maintenance, please call Sterilizer Autoclave Solutions at 704-9661650 or visit us on the web at

If you need any Midmark Parts, you can find them at the following links!


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