Fisher and Paykel Healthcare MR730
Fisher and Paykel Healthcare · Model MR730
Fisher & Paykel Healthcare MR730.
Typical Failure Modes
Compiled for this model from its own documentation and established engineering knowledge for this equipment class - not from a verified service record. Confirm against the manufacturer's service manual.
Chamber not heating to target humidity / temperature
HighSymptoms: Low airway temperature, condensation or dryness, temperature not reaching set point.
Root cause: Water chamber not seated on the heater plate, a failed heater base plate, or a temperature-probe fault.
Heater-wire circuit alarm
MediumSymptoms: "F-2" - heater-wire fuse F2 open circuit; airway heater not working.
Root cause: Open heated breathing circuit, a faulty heater-wire adapter, or (MR730) the F2 fuse.
Temperature probe fault
MediumSymptoms: Implausible temperature, probe-fault alarm, unit will not run.
Root cause: Damaged airway or chamber temperature probe or its connector.
Error code Ec / En / EXx
HighSymptoms: "Ec" (checksum / EPROM), "En" (RAM), "EXx" (multiplexer / ADC over- or under-flow).
Root cause: Internal electronics fault - the unit stops in a fail-safe mode; refer for service.
Water-out / chamber fault
MediumSymptoms: Chamber runs dry, water-out alarm, auto-feed not maintaining level.
Root cause: Empty supply bag, a stuck float valve, or a cracked chamber.
Serviceable Parts & Consumables
Serviceable items for this model, compiled from its documentation and engineering knowledge for this equipment class. Service class and relative cost are estimates, not manufacturer figures; no part numbers are given. Confirm intervals and pricing against the manufacturer.
Heater base plate
Class Major service partRel. cost $$$R&R Difficult
Temperature probe set (airway + chamber)
Class Frequent wear itemRel. cost $$R&R Easy
Heater-wire adapter / F2 fuse
Class Periodic replacementRel. cost $R&R Fairly easy
Water chamber
Single-patient or per-protocol consumable.
Class Frequent wear itemRel. cost $R&R Easy
Auto-feed / float valve assembly
Class Periodic replacementRel. cost $$R&R Moderate
| Part | Service class | Relative cost | R&R difficulty |
|---|---|---|---|
| Heater base plate | Major service part | $$$ | Difficult |
| Temperature probe set (airway + chamber) | Frequent wear item | $$ | Easy |
| Heater-wire adapter / F2 fuse | Periodic replacement | $ | Fairly easy |
| Water chamber Single-patient or per-protocol consumable. | Frequent wear item | $ | Easy |
| Auto-feed / float valve assembly | Periodic replacement | $$ | Moderate |
Relative cost: $ lowest · $$$$ highest service-part cost for this equipment class. Not a price.
Error Codes
Extracted directly from this unit's own service manual.
EcChecksum error (possible failure of U1 EPROM)
EnMemory test error (possible failure of U4 RAM)
EXxWhere X = 0 through 7, indicating multiplexer stage where error occurred. Where x = o or u, indicating ADC overflow error or underflow error, at the indicated multiplexer stage. (ADC counts outside the expected range will generate either an under or overflow error)
b-1The Mute button is on at turn on or has been on for > 5 minutes.
b-2The Standby button is on (see b-1 above)
F-2The Heater Wire fuse, F2 is open circuited.
--- Temperature sensor probe faultTemperature sensor probe fault (see Sect.3.1)
EP1Hardware fault; Q13 short not effective.
EP2Low probe temperature (~0 °C).
EP3High probe temperature (~70 °C).
EP4Partial short between the active probe cable conductors.
Troubleshooting Approach
A starting sequence for this model, compiled from its documentation and engineering knowledge for this equipment class. Follow the manufacturer's service documentation for the actual procedure.
Symptom: Not reaching target humidity/temperature
- Confirm the water chamber is fully seated and latched on the heater plate and has water.
- Check the airway and chamber temperature probes and connectors; swap in a known-good probe set.
- Confirm the heated breathing circuit is intact and the heater-wire adapter is connected.
- Check the F2 heater-wire fuse if "F-2" is shown.
- If it still will not heat, replace the heater base plate.
Symptom: Error code Ec / En / EX
- Note the exact code and the multiplexer stage if shown.
- Power-cycle the humidifier.
- Try a known-good probe set to rule out a sensor cause.
- If the code returns, the unit is in fail-safe - remove from service.
- Refer to Fisher & Paykel service with the code.