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What This Guide Helps With
Troubleshooting excessive chamber pressure caused by cycle selection, loading, vent restrictions, sensing problems, or unsafe pressure-control conditions.
Step-by-Step Troubleshooting
1. Protect Personnel and Prevent Load Release
Do not approach, open, move, or service a sterilizer that is actively overpressurized or releasing steam. Keep personnel clear of the door, safety valve, and exhaust path. Stop clinical use according to facility emergency procedures. Quarantine the load. Allow the unit to cool and depressurize without forcing the door. Use another verified sterilizer for needed instruments.
Expected outcome: Personnel are protected from steam, hot water, and unexpected door movement.
2. Confirm the Reported Overpressure Condition
Determine:
- The displayed pressure when the concern occurred.
- The selected cycle.
- Whether the pressure continued rising.
- Whether the safety valve released.
- Whether the cycle aborted automatically.
- Whether the reading remained high after cooling.
- Whether the concern was based on the display, a gauge, or visible steam release.
- Do not assume the display value is accurate or inaccurate without verification.
Expected outcome: The condition is clearly documented and distinguished from normal cycle pressure.
3. Verify the Correct Cycle and Configuration
Confirm that:
- The intended cycle was selected.
- The load is compatible with that cycle.
- No unauthorized program or setting change was made.
- The displayed cycle parameters match the department’s approved process.
- Date, time, and operator entries did not obscure the actual cycle selection.
- Do not alter protected service-level parameters.
Expected outcome: The sterilizer is configured for an approved cycle. If incorrect cycle selection caused the concern and subsequent testing is normal, stop troubleshooting.
4. Inspect the Load for Steam-Flow Restrictions
After the chamber is cool and fully depressurized:
- Check for overloading.
- Verify packs are not tightly compressed.
- Confirm trays and containers are arranged correctly.
- Ensure materials are approved for steam sterilization.
- Check that no item blocks accessible chamber openings or drain screens.
Expected outcome: The chamber is loaded in a manner that permits normal steam flow. If proper loading prevents recurrence, stop troubleshooting.
5. Check Drain and Exhaust Tubing
Inspect accessible external drain and exhaust paths for:
- Kinks.
- Pinched tubing.
- Improper routing.
- Obstruction at the facility drain.
- A full collection container.
- Tubing submerged in standing water.
- Loose or incorrectly installed connections.
- Do not disconnect tubing while the chamber is hot or pressurized.
Expected outcome: Exhaust and drain paths are unobstructed. If correcting the restriction restores normal operation, stop troubleshooting.
6. Inspect Accessible Vent and Drain Areas
With the unit cool and electrically isolated as required:
- Inspect accessible chamber drain screens or strainers.
- Remove only loose debris that can be cleared without disassembly.
- Check for packaging material or mineral buildup around accessible openings.
- Do not probe internal valves or plumbing.
Expected outcome: Accessible flow paths are clean. If an approved test cycle completes with normal pressure, stop troubleshooting.
7. Observe the Door and Safety Valve Area
During a controlled test only when safe:
- Remain clear of the door and valve discharge path.
- Observe whether the safety valve releases repeatedly.
- Listen for abnormal venting or chattering.
- Check whether the pressure display changes smoothly.
- Stop the test if pressure appears uncontrolled or steam releases abnormally.
Expected outcome: Pressure remains controlled and the safety valve does not release unexpectedly. Any abnormal release requires removal from service.
8. Compare the Pressure Indication With Approved Test Equipment
Qualified personnel may compare the sterilizer’s pressure indication using approved test equipment and manufacturer procedures. Do not adjust calibration based only on a visual impression. Do not continue cycling the unit when the pressure indication is questionable. Preserve the cycle record and observed readings for service evaluation.
Expected outcome: Pressure indication is verified as reasonable and stable. If verification fails, remove the sterilizer from service.
9. Perform Final Functional Verification
When no unsafe condition remains and an external cause was corrected:
- Run the approved test cycle.
- Observe pressure rise, holding phase, and exhaust.
- Confirm pressure does not continue rising beyond the expected cycle behavior.
- Verify the cycle completes without safety-valve release.
- Complete required quality-control testing.
Expected outcome: Chamber pressure remains controlled throughout the cycle. Troubleshooting can stop after all required tests pass.
10. Remove From Service for Any Recurrent Overpressure
Immediately remove the unit from service when:
- Pressure continues rising unexpectedly.
- The safety valve releases prematurely or repeatedly.
- The pressure indication is unstable or implausible.
- Exhaust does not occur normally.
- The door appears distorted, damaged, or difficult to operate.
- Steam releases from an unintended location.
Expected outcome: A potentially hazardous pressure vessel is not used clinically.
If the Problem Persists
External loading, cycle selection, and exhaust restrictions have been ruled out. Possible remaining categories include pressure or temperature sensing, vent or exhaust control, heater control, safety-valve performance, internal plumbing restriction, control circuitry, or calibration. The sterilizer should be:
- Removed from service.
- Labeled Out of Service.
- Sent for repair or bench evaluation.
- Evaluated using appropriate Tuttnauer documentation and approved pressure and temperature test equipment.
- Repaired, calibrated, or configured only by qualified personnel.
- Return to service requires documented functional, pressure-control, safety, and sterilization-quality verification. Knowing when to stop external troubleshooting is proper troubleshooting.
Clinical Use Tip
Never force the door or stand in front of it while chamber pressure remains above a safe released condition.
Work Order Documentation (CCR Method)
CCR = Complaint, Cause, Resolution
Complaint
What was reported by the clinical staff.
Example:
"Sterile Processing reported that chamber pressure rose abnormally and the cycle stopped before completion."
Cause
What was observed during troubleshooting.
Example:
"Clinical Engineering found the external exhaust tubing pinched between the sterilizer and the counter."
Resolution
What action was taken.
Example:
"Rerouted the tubing, completed an approved cycle with stable pressure and normal exhaust, and returned the unit after required quality testing passed."
Helpful Details to Include (If Known)
- Cycle selected.
- Load contents and arrangement.
- Highest displayed pressure.
- Safety-valve behavior.
- Cycle phase at shutdown.
- Drain and exhaust routing.
- Chamber drain-screen condition.
- Pressure indication after cooling.
- Steam leakage location.
- Results of pressure verification.
- Final cycle and quality-control results.
- Final device status.
Final Thought
Overpressure concerns require immediate attention to personnel safety. Verify cycle selection, loading, exhaust routing, and accessible flow paths before suspecting internal control failure, then escalate promptly when pressure cannot be confirmed as stable and safe. That is successful troubleshooting.