This is the question that catches most dental practices out at a CQC inspection. Everyone knows their autoclave needs an “annual service.” Almost nobody can correctly separate which of the three things that actually means is the service, which is the validation, and which is the pressure vessel inspection. They’re three different jobs under three different rules, and getting any one of them wrong is a finding waiting to happen.
Here’s what HTM 01-05 actually says, what it actually requires, and how to think about the schedule properly.
This is the bit that surprises people. HTM 01-05 doesn’t mandate a fixed service interval. It defers to the manufacturer. The exact wording at paragraph 12.1 of the 2013 NHS England guidance is:
“The sterilizer should be maintained and serviced in accordance with the manufacturer’s instructions.”
And at paragraph 11.1:
“All decontamination equipment should be subjected to validation, testing, maintenance and servicing as recommended by the manufacturer/supplier. All records of these procedures should be retained for audit/inspection.”
So the answer to “how often should I service my autoclave” isn’t in HTM 01-05. It’s in your autoclave’s instruction manual. Most established European manufacturers converge on annual servicing, the brands we supply (Castellini, Stern Weber, Mocom) all sit on that schedule. Cassette-style autoclaves are the outlier and often require a six-month consumables check on top of the annual visit.
The thing HTM 01-05 is prescriptive about, and where the “annual” word genuinely lives, is validation. Paragraph 12.2:
“Validation is needed for new equipment at installation and annually thereafter. It will also be necessary to validate equipment after any major repairs have been carried out.”
That’s a real annual obligation. The annual service sits alongside it as a manufacturer requirement, not an HTM 01-05 one. Most practices do them in the same visit because it makes scheduling easier and saves a call-out fee.
Worth unpicking properly because they really are different jobs.
Service is the preventive maintenance visit. The engineer replaces consumable parts (door seal, filters, water-side seals), checks the safety valve, runs the pump against spec, descales the chamber, updates firmware where supported, and writes a service certificate. This is what HTM 01-05 says you do “in accordance with the manufacturer’s instructions.”
Validation is the performance test. Independent calibrated probes go into the chamber, the engineer runs a series of cycles (small load, large load, dryness tests on vacuum machines), and prints a report showing the cycle actually hits its target temperature, pressure and dwell time. This is what HTM 01-05 mandates annually.
Pressure Vessel Inspection (PVI) is the statutory examination under the Pressure Systems Safety Regulations 2000. HTM 01-05 paragraph 4.10 cross-refers: every steam steriliser is subject to PSSR and must be examined periodically by a Competent Person (Pressure Vessels). CQC’s Dental Mythbuster 12 puts the legal ceiling on the interval:
“The maximum interval between these safety inspections is 14 months.”
Three jobs, three rules, three certificates. Most practices schedule all three into one annual visit. Some have them done separately. The compliance question CQC will ask isn’t “how many visits did you have”, it’s “can you show me the certificate for each of the three things.”
These sit alongside the annual service and validation. They aren’t service work, they’re operator-level checks the dental team runs themselves. HTM 01-05 Chapter 12 lays them out cleanly:
Daily. The Automatic Control Test runs on every cycle (the machine prints it for you). A steam-penetration test: Bowie-Dick or Helix, runs once at the start of clinical use on vacuum (Type B and S) machines.
Weekly. The air-leakage test on vacuum machines, the residual-air test on Type N or S. User-level checks.
Quarterly. Thermometric tests by a Competent Person (Decontamination) or service engineer. These are the deeper checks that go beyond daily/weekly, your service company runs them.
Annual. Full validation as above. Done by the service engineer or Competent Person (Decontamination).
If you’re keeping a clean logbook with all of these recorded, you’re in good shape. If you’re not, that’s where the compliance gap opens up. HTM 01-05 paragraph 11.3 is the line that catches people out:
“Failure to perform these tasks or retain evidence of their performance may indicate non-compliance of the decontamination process.”
That’s the bit that matters. Even a working machine that’s been silently failing tests for six months looks like non-compliance if there’s no paperwork showing someone noticed and did something about it.
There’s no statutory list, HTM 01-05 hands the scope to the manufacturer’s IFU. But across the major manufacturers, a standard annual service for a B-type benchtop autoclave should include:
If you’re paying for an annual service and not getting a signed certificate with that list of items completed, you’re paying for less than you should be getting.
Honest indicative pricing for an annual service on a B-type benchtop autoclave from competing UK providers, ex VAT:
For comparison, our published prices sit in the middle of that range. Service is £185, Service + PVI is £235, and the full bundle is £450, all ex VAT for B-type. The N-type prices are slightly lower. These are on our service & maintenance page.
What the bundle saves you isn’t really money, it’s organisational headache. One visit, one engineer, one paperwork pack covering all three certificates. Versus three visits and three engineers chasing each other through your calendar.
The one we hear most often: “I’ll service it when it stops working.”
That argument fails on three counts. It’s not legal: a sterilizer without a current PSSR Written Scheme of Examination certificate is in breach of the regulations regardless of whether it’s running fine, and the 14-month ceiling on PVI is a maximum, not a “when convenient” deadline. It’s not what HTM 01-05 says: paragraph 11.3 makes the absence of documentation itself the non-compliance, even if the machine works. It’s not what your manufacturer says: every major UK-installed brand publishes a time-based service interval, not a fault-based one.
A working autoclave that has never failed a cycle can still fail CQC, still breach PSSR 2000, and still void its manufacturer warranty. The clock runs on the calendar, not on the machine.
If you’re starting from scratch, the cleanest approach is to align everything around your installation date plus 12 months. Service, PVI, and validation all booked into one visit annually. Then the next year, same date, same engineer, same paperwork pack. The diary doesn’t drift, you never face a 14-month PSSR gap, and your logbook tells a clean story to any inspector.
If you’ve inherited a clinic with paperwork scattered across the year, pick one of the three dates as your anchor and pull the others toward it over the next two annual cycles. We help practices do this routinely.
The one date you absolutely cannot let slip is the PVI. Validation and service can run a few weeks late without serious consequence, the PVI is a statutory ceiling. If your last PVI certificate was 13 months ago, you’ve got a month to sort the next one. Past 14 months and you’re operating in breach of PSSR 2000.
If you’d like one annual visit covering service, PVI and validation with a single price quoted up front, that’s what our Service + PVI + Validation bundle does. £450 ex VAT for a B-type, £395 for an N-type. You get a service certificate, a PVI written scheme of examination, and a calibrated probe validation report, all from one engineer visit.
If you’d rather start with just one piece, say, you’ve already got the PVI sorted through your insurer and just need the service and validation, we can split it. Ring us on 01274 265566 and we’ll work out which bits you actually need versus what’s already covered elsewhere.
The longer answer on what HTM 01-05 validation involves is in our HTM 01-05 validation explainer. The CQC-inspection angle is in the practical guide for practice managers.
