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What This Guide Helps With
Addresses weak, absent, or interrupted circulation caused by load setup, blocked spray paths, disconnected tubing, low supply flow, or internal pumping faults.
Step-by-Step Troubleshooting
1. Protect Patients and Reprocessing Workflow
Treat any endoscope from a cycle with inadequate circulation or spray flow as incompletely reprocessed. Quarantine the endoscope and transfer it to another verified AER.
Do not continue the cycle merely because fluid is visible in the chamber.
Expected outcome: Endoscopes are not released after an unverified circulation phase.
2. Confirm the Exact Flow Condition
Record the exact alarm and determine whether the problem involves:
- No visible circulation
- Weak spray
- Intermittent flow
- One chamber
- One endoscope channel
- All connections
- A pump that is silent
- A pump that sounds abnormal
- Flow failure during a specific cycle phase
Expected outcome: The issue is separated into chamber circulation, connection, load, water-supply, or internal pump categories.
3. Inspect Endoscope and Accessory Setup
Verify that the correct approved connectors, tubing, channel adapters, and accessories are installed for the endoscope being processed. Check for:
- Loose connections
- Incorrect adapter
- Kinked tubing
- Clamped tubing
- Reversed routing
- Disconnected channel line
- Tubing trapped beneath the scope
- Missing accessory
Do not improvise adapters or connections.
Expected outcome: The endoscope and all approved accessories are connected and routed correctly. If correcting the setup restores flow, proceed to verification.
4. Check Chamber Loading and Positioning
Confirm that the endoscope is positioned according to the validated process and does not block spray outlets, accessible strainers, moving components, or fluid return paths.
Remove excess items or incorrectly placed accessories.
Expected outcome: The load permits unrestricted spray, circulation, and drainage.
5. Inspect Accessible Spray and Flow Paths
With the AER safe and idle, inspect accessible spray outlets, chamber surfaces, and strainers for visible debris, labels, packaging fragments, or mineral buildup.
Clean only removable or accessible components covered by approved operator or maintenance procedures. Do not probe internal ports with tools.
Expected outcome: Accessible flow paths are clean and unobstructed.
6. Verify Incoming Water and Chemical Supply
Check that water valves are fully open, supply hoses are not kinked, and no low-water alarm is present. Confirm that required disinfectant and detergent supplies are correctly installed and not empty.
Inadequate incoming supply can appear as a circulation problem.
Expected outcome: The AER has adequate water and chemical supply for normal circulation.
7. Check for External Leakage
Inspect the chamber, doors, external tubing, utility connections, and floor around the AER for leakage. Stop testing immediately if chemical or water leakage is present.
Do not tighten internal fittings or remove panels.
Expected outcome: The fluid path remains contained, with no visible external leak contributing to low flow.
8. Listen for Abnormal Operation
During an approved empty or verification cycle, listen for normal pump operation. Note:
- No pump sound
- Repeated starting and stopping
- Grinding
- Cavitation-like noise
- Excessive vibration
- Flow beginning and then stopping
Do not continue repeated tests when abnormal mechanical noise is present.
Expected outcome: The pump runs smoothly and visible circulation is consistent, or an internal service-level problem is confirmed.
9. Perform a Controlled Functional Verification
Run the approved verification cycle with the correct accessories. Confirm:
- Normal chamber spray
- Continuous circulation
- No flow alarm
- Correct progression through circulation phases
- Complete draining
- No leakage
- Successful cycle record
Expected outcome: Flow remains stable throughout verification. The issue is resolved, and troubleshooting can stop.
10. Stop and Escalate When Flow Remains Unreliable
If load setup, tubing, accessible spray paths, water supply, chemical supply, and leakage checks are acceptable but circulation remains weak or absent, remove the AER from service.
Do not disassemble pumps, valves, manifolds, channel blocks, or flow sensors.
Expected outcome: The AER is prevented from processing endoscopes until required flow is restored and verified.
If the Problem Persists
Common loading, accessory, supply, and accessible-obstruction causes have been ruled out. The remaining problem may involve an internal circulation pump, valve, manifold, pressure or flow sensor, internal tubing restriction, motor control, or software command issue.
The AER should be:
- Removed from service
- Labeled Out of Service
- Sent for repair or qualified bench evaluation
- Evaluated using appropriate manufacturer documentation and approved test equipment
- Repaired or configured only by qualified personnel
Return to service requires verification of chamber circulation, channel flow where applicable, leak integrity, alarms, drainage, and complete cycle performance. Knowing when to stop external troubleshooting is proper troubleshooting.
Clinical Use Tip
Visible fluid in the chamber does not confirm that all required endoscope channels received adequate flow.
Work Order Documentation (CCR Method)
CCR = Complaint, Cause, Resolution
Complaint
What was reported by the clinical staff.
Example:
"Sterile Processing reported weak spray flow and a circulation alarm during an Advantage Plus cycle."
Cause
What was observed during troubleshooting.
Example:
"Clinical Engineering found one external channel tube kinked beneath the endoscope in the chamber."
Resolution
What action was taken.
Example:
"The tubing was rerouted and connected correctly, and an approved verification cycle completed with continuous circulation, normal spray flow, and no alarms."
Helpful Details to Include (If Known)
- Exact flow alarm
- Chamber affected
- Cycle phase
- Endoscope and connector type
- Tubing condition and routing
- Load placement
- Visible debris or obstruction
- Water and chemical supply status
- Leakage
- Pump sound
- Verification-cycle result
- Final device status
Final Thought
Protect the patient by treating every flow-interrupted cycle as incomplete, verify load setup and external supply paths before assuming pump failure, confirm circulation through a complete test, escalate safely, and document the exact flow path corrected.
That is successful troubleshooting.