Infusion pumps are among the most-serviced devices in any hospital. Most calls are not actually pump failures — they are set issues, user errors, or sensor contamination. Knowing which is which fast keeps clinical floors moving.
This guide covers the alarms and failure modes that drive the bulk of infusion pump service calls, the typical cause distribution, and the diagnostic sequence that gets you to a confirmed answer.
Occlusion alarms — upstream and downstream
Downstream occlusion is the most common alarm. The vast majority resolve at the bedside before biomed gets called — kinked tubing, closed clamp, infiltrated IV site, patient lying on the line.
When the alarm persists after the set and site are cleared, the diagnostic chain on the pump itself is:
- Confirm the alarm reproduces with a known-good administration set on a test fluid bag
- Check the pressure sensor / strain gauge for residue from prior leaks (a thin film of dried medication is a classic false-occlusion cause)
- Verify door closure switch and tubing seating — many pumps fault occlusion if the door reed switch is dirty
- Run the OEM diagnostic mode for pressure transducer calibration
- If still failing, replace the pressure sensor assembly per OEM
Air-in-line alarms
Air-in-line sensors are ultrasonic. False alarms come from sensor contamination, set placement, or the sensor losing acoustic coupling.
- Clean the air-in-line sensor face with isopropyl per OEM IFU — never abrasives
- Verify the set is fully seated in the sensor channel (most common cause)
- Confirm fluid is fully primed — micro-bubbles from rapid priming trigger alarms
- Test with a known-good set and IV fluid (saline, not water — water has different acoustic properties)
- If reproducible with a verified set, run OEM diagnostic — sensor replacement is the typical repair
Flow rate accuracy issues
Flow rate verification belongs in every infusion pump PM. Use a calibrated flow analyzer (e.g., Fluke IDA-5) and OEM-specified administration sets. Tolerance is typically ±5% per OEM, but check your device — some neonatal pumps are tighter.
When flow is out of spec:
- Confirm the correct set type is selected on the pump (set-type errors cause apparent flow inaccuracy without a hardware fault)
- Inspect the pumping mechanism — peristaltic fingers, cassette interface, or syringe driver — for wear
- Check motor drive belts and gears where applicable
- Verify with a fresh OEM administration set; older or third-party sets degrade accuracy
- Run OEM flow calibration routine if available; otherwise the rotor / cam assembly may need replacement
Battery and power issues
- Battery runtime below OEM spec almost always means the battery, not the charging circuit — but verify with a fully charged battery test before replacing
- Battery age matters more than cycle count for Li-ion packs; replace per OEM interval even if "fine"
- AC power faults that clear with a known-good cord = cord; faults that persist with a known-good cord = internal power supply
When the pump "fails" but you cannot reproduce it
Intermittent faults are real. Log the exact alarm code, the user-reported scenario (drug, rate, set type, patient position), and run an extended monitoring PM. Pulling the device out of service for an unconfirmed intermittent is sometimes the right call — document the rationale.
Always check the OEM for active Medical Device Alerts (MDAs) on the model. A high rate of "no fault found" on a specific model often correlates with a published OEM advisory.