Your Sterilizer Machine Maintenance Plan

As we’ve noted in the past, developing just three good sterilizer machine habits can easily save you thousands of dollars.

But if you want to get the most out of your autoclave (and stay on the right side of best-practices, industry standards, and government recommendations and regulations) you need a maintenance plan with a little bit of structure. Although you’ll always want to check with your supplier/manufacturer (or the manual that came with your sterilization machine) prior to doing any maintenance, the following are good preventative care practices for most steam autoclaves.

But the most important part of your maintenance plan is to Keep an accurate Maintenance Log! Good record keeping makes it much easier to pinpoint recurring issues, and is invaluable if you have to call in a service technician or work with the manufacturer to resolve lingering problems.

Daily Sterilizer Machine Maintenance

  • Basic Wipe Down: Wipe down your sterilizer machine with a damp cloth—paying special attention to the inside of the chamber.  This prevents the build-up of spilled media, potentially corrosive chemicals, or residual fluids from waste loads.
  • TIP: If you regularly process waste loads, place your red bags in a SOLID STEEL TRAY before putting them in the autoclave. The tray catches drips, leaks, and boil-overs, ultimately saving you a great deal of time and money on repairs.

Weekly Sterilizer Machine Maintenance

  • Full Autoclave Cleaning: Check the exterior of the machine and the inside walls of the pressure vessel for general cleanliness, particularly around operating parts and external switches and sensors. In most cases, you can clean your autoclave chamber with nothing more than a plastic (not metal!) kitchen scouring pad and water or mild dish soap.  Pay special attention to the the heating element (if you have an in-chamber heater) and any exposed sensors, removing any scale deposits. (Scale interferes with the functions of these components.)  Finally, use anti-bacterial wipes to clean exterior panelling.
    • TIP: NEVER use abrasive or chemically aggressive cleaners on the sterilizer machine’s pressure vessel! Chlorine-, hydroxide-based, or other aggressive cleaners can damage the pressure vessel and other components.  Use a bleach-free, chlorine-free all-purpose spray cleaner suitable for stainless steel, such as Fantastik All-Purpose spray cleaner or Formula 409 All-Purpose cleaner. If you have mineral deposits to remove, use a mild descaling agent containing phosphoric acid (CLR is a popular brand).  Be sure to thoroughly flush the chamber after cleaning.
  • Door Check: Check the free movement of the door and any locking mechanisms. If the door does not lock and release smoothly, first look for obstructions, and then check the closure arms, hinges, and points where the door mates with the body of the autoclave.  Moving parts and mating faces may perform best when lightly coated with high-temperature copper grease (sold at most auto supply stores; check with your manufacturer for details).
  • Gasket Check: Note the condition of the door’s sealing gaskets; keeping them clean will prolong their working life (always replace them as soon as they show damage, as a matter of both efficient operation and safety).  Many gaskets will also last longer if regularly coated with a thin layer of grease (most need a high-temperature grease, such as “high-vacuum” silicone grease—check your manual for details or contact your manufacturer).
  • Drain Check and Vent: If the autoclave has been plumbed directly into a drain using flexible tubing, this should be checked for any signs of blockage or damage. Also check that both ends of the tube are securely connected. Check the autoclave’s safety valve outlet for any obstruction.

Monthly Sterilizer Machine Maintenance

  • Remove Standing Water: Prior to the regular weekly Full Cleaning, remove any standing water from the chamber or reservoir (a consumer-grade “wet/dry” shop vacuum is ideal for this).  Now wipe down the heating elements (if accessible), water level probe(s), chamber interior, etc. Be sure to wipe away any spilled media, accumulated scale, waste residues, etc. (making sure to use gentle cleaners, as noted in the Weekly Maintenance section). Finally, wipe all exterior surfaces down using anti-bacterial wipes.
  • Check General Operation: Run your most common cycles to confirm they are performing consistently and as expected. Note any errors, warnings, or irregularities in the Maintenance Log and address them immediately.

Bi-Annual Sterilizer Machine Maintenance (performed every six months)

  • Scale Prevention: Every water supply contains trace minerals.  These tend to slowly accumulate in the autoclave chambers and plumbing, and especially on in-chamber heating elements. Scale build-up will significantly impact autoclave performance and decrease operational lifetime. Distilled white vinegar (available at any grocery store) can be used to prevent scale accumulation. Fill the autoclave with a 50/50 solution of distilled white vinegar and water, and then run a normal cycle. Once the cycle is complete, thoroughly flush the chamber, and run a second empty load before returning to normal operation.
  • Temperature Control and Pressure Gauge Check: Run the autoclave. Five minutes into the dwell stage check the reading shown on the temperature display and pressure gauge.  Do they match what’s show on the Steam Table (below)? Check again five minutes later. A consistent disparity between your readings and those in the table indicates trapped air or a calibration problem. Note these discrepancies in the Maintenance Log, and contact your manufacturer or technician.
steam table: temperature/pressure correlations for autoclave sterilizer machines
a steam table showing temperature/pressure correlations for autoclave sterilizer machines
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