GE R860: exhale valve and flow sensor tests fail at service check
What happened
At the service check, the exhale valve test and the exhale flow sensor test fail while everything else passes. Replacing the external plastic valves changed nothing, and the same exhale valve and flow sensor pass on another machine.
What was checked
- Replaced the external plastic valves — no change.
- Cross-tested the exhale valve and exhale flow sensor on another unit of the same model — both pass there.
- Ran the service calibration and test cycle.
Cause
Not confirmed. The suspicion in the case was the board that carries the connector for the exhale flow sensor: if that board is faulty, the flow signal is wrong, and on its own that can fail both the flow sensor test and the exhale valve test that relies on the same reading. Colleagues noted this board had given trouble before — as reported in the case, not a rule.
The cause is probable and was not fully confirmed.
What was done
Probable, not confirmed in the case. The recommended step was to check the suspected board with the exhale flow sensor connector and replace it if faulty, then run the deeper service-level diagnostics and calibration — a procedure from the manufacturer's service documentation, done by authorised personnel.
Safety
Before opening the machine, power it down and isolate it from mains, and after any board or sensor work complete the electrical safety test and full performance verification before the ventilator returns to patients.
Lesson: When two exhale-side tests fail together but the valve and sensor pass on another unit, suspect the electronics that read the sensor, not only the pneumatics.
Covered in the course: Ventilator Service — Level 2: Fault-Finding →
Written from an anonymised case shared by service engineers. It is not a manufacturer instruction and grants no authorisation. Independent note; names are trademarks of their owners.