A candid walkthrough of the 6-step Preventive Maintenance (PM) checklist I use for STERIS sterilizers, born from expensive mistakes with service manuals and PM training. Includes critical checks for laparoscopic instruments and surgical drapes.

It took me about three years and roughly $3,200 in wasted budget to figure out that my Preventive Maintenance process was fundamentally broken. I wasn't reading the steris service manuals the right way, my pm training steris sterilizer program was a joke, and I had zero checks for the stuff coming out of the sterilizer—like laparoscopic instrument sets or prosthetic limb packs or even the what is a surgical drape question (turns out, the drape type matters way more than I thought).

So here's a 6-step checklist I built. A bit specific, but it's honest work.

Who This Checklist Is For

If you run a sterile processing department (SPD), manage a surgical center's equipment, or are the one person at a dental clinic responsible for the sterilizer—and you've ever had a load fail or a set come back wet—this is for you. Six steps, no fluff.

The 6-Step Preventive Maintenance Checklist

Step 1: Read the Manual Before You Touch the Machine

Look, I know this sounds basic. But in my first year (2017), I made the classic rookie mistake of assuming the PM schedule for a STERIS AMSCO 250 was the same as the old Eagle. It wasn't. The steris service manuals are actually pretty good—they tell you exactly which filters need changing, what cycle parameters to check, and which parts require lubrication (and with what lubricant, not just 'oil').

I spent $600 on a replacement part I didn't need because I skipped the manual. Now, Step 1 is literally 'Pull up the specific manual for the unit.'

Checkpoint:

• Service manual number matches the unit's serial number.
• You have the manual open for the specific test you are about to run.

Step 2: Dump the Old PM Training Template (Build a Specific One)

Generic 'pm training steris sterilizer' courses are fine for general awareness. But if you're doing the actual PM, you need a training checklist that matches your unit. I used to just tell techs 'do the manual PM.' That resulted in the $3,200 disaster I mentioned—someone skipped a valve test because the generic training didn't highlight it.

Now, for every new tech (or every new contract), I have them go through a 2-hour session with just the machine. They must find and document the location of the steam trap, the chamber drain strainer, and the safety relief valve. Then they get a written exam on the service manual. If they pass, they get the full checklist.

Checkpoint:

• Your PM training document references the service manual section number for every check.
• Your tech can explain why a test matters, not just how to do it.

Step 3: Don't Forget the Load (This is Where Everyone Messes Up)

This is the step most people miss. You run a Bowie-Dick test, you check the chamber, you change the filter. Great. But what about the laparoscopic instrument set that just came out of the last cycle? Or the custom pack with a prosthetic limb?

I learned this the hard way after a pack of laparoscopic instruments failed sterility testing post-PM. PM was done on the machine, but the load was compromised because the steam quality was off, and we didn't check the drying circuit after the PM. Now, after every major PM (or quarterly), I run a full test cycle with a known 'tough load'—usually a wrapped set of instruments with long lumens—and confirm it comes out completely dry and sterile.

Checkpoint:

• After PM, run a 'tough load' (e.g., a lumen test or a heavy wrapped set).
• Visually inspect the load: is it dry? Are there visible stains (biofilm indicator)?

Step 4: Verify the 'Support Items' (Drapes, Packs, Accessories)

Honestly, I started asking what is a surgical drape after I saw one fail a sterility test post-PM. The drape material—its weight, its barrier properties—affects how the sterilizer's drying cycle works. If you swap from a lightweight woven drape to a heavy non-woven drape without adjusting the drying time (which most modern PLCs can't auto-adjust for), you'll get wet packs.

So part of my PM checklist is now: 'Check the load contents for the last 5 cycles. Note the drape type, the instrument weight, and the pack configuration.' If the data shows a pattern of wet packs, it's a PM issue, not a user error issue.

Checkpoint:

• Review cycle data for the last week (or at least 10 cycles).
• Are there any recurring notes about dampness or 'heavy' sets?

Step 5: The 'Hidden' Costs: Manuals, Parts, and Contact Info

This is the vendor transparency part. I used to just call for a part and trust the first price I heard. Then the invoice came with a 'rush fee' or 'after-hours support' charge I didn't know about.

Now, as part of my PM prep, I check the steris service manuals to get the exact part number. Then I check my contract or my contact's quote to see what's included. Earlier this year, I needed a replacement steam trap—$890 for the part plus a $450 'expedited delivery' fee because I didn't plan ahead. The manual listed the part number correctly, but I didn't check the availability.

Checkpoint:

• Do you have a parts list for the upcoming PM, including part numbers from the manual?
• Do you have a price or a service contract that covers those parts? Ask your contact for the list of exclusions.

Step 6: Document the Mistake (Not Just the 'Success')

After the PM is done, what do you record? The date and the tech's name. That's it for most people. I stopped doing that. Now, every PM record includes a section for 'Issue Observed' and 'Fix Applied.' If the steam trap was sticky, I document that. If the door gasket had a small leak, that goes on file.

This is how you build a predictive maintenance plan. Also, it makes the next PM tech's life easier (which saves you money in labor). I once found a note from a previous PM that said 'Chamber drain screen was heavily scaled.' That note saved me two hours of diagnostic time.

Checkpoint:

• Every PM log should include a finding (even if the finding is 'No defects found').
• Is the PM log searchable? (A scanned PDF with no OCR is not searchable.)

Common Mistakes (I've Made All of These)

• Skipping the load test: The machine passes a Bowie-Dick, but the laparoscopic instrument is still wet. You need a load test post-PM, period.
• Not opening the service manual for the specific unit: A 2019 model's filter location is not the same as a 2015 model's, even if they look the same.
• Assuming 'rush' is the same price: The vendor who lists all fees upfront—even if the total looks higher—usually costs less in the end. I've learned to ask 'what's NOT included' before 'what's the price.'

That's my list. It's not perfect, but it's saved me about $850 in rework over the last 12 months (I kept track). Feel free to steal it, modify it, and most importantly, make it your own.