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5.2. Troubleshooting
5.2.1. Low Temperature
Condition detected
Possible cause
Action to take
Temperature less than
desired, no alarm.
Humidifier warming up.
Wait for a few minutes.
Airway temperature low
alarm activated.
Temperature probe not in position.
Check position of temperature probe in the
circuit.
Gas flow stopped or interrupted.
Turn humidifier off until gas flow resumed.
Temperature probe not in probe housing.
Fit temperature probe.
Gas flow rate too low.
Increase gas flow to more than 5 liters per
minute.
Chamber temperature
low alarm activated.
Too much distance between end of heater wire
and temperature probe.
Use longer heater wire or shorten
inspiratory hose so that distance is
between 25 (1”) and 100 mm (4”),
ideally 30mm.
Poor thermal contact between base of chamber
and heater plate.
Check that chamber base and heater plate
are clean, smooth and flat.
If necessary clean or replace.
Temperature probe not inserted at chamber
outlet.
Fit temperature probe correctly.
Heater element needs replacement.
Send for repair.
5.2.2. High Temperature
Condition detected
Possible cause
Action to take
Airway temperature
high alarm
activated.
Sudden spurious increase in gas flow.
Wait for temperature to fall below
threshold.
Heater wire too close to temperature probe.
Use shorter heater wire or lengthen
inspiratory hose so that distance is between
25 (1”) and 100 mm (4”), ideally 30 mm.
Possibly faulty Airway sensor on temperature
probe (low resistance).
Check probe.
Chamber temperature
high alarm activated.
No water in chamber.
Refill humidification chamber.
Possibly faulty Chamber sensor on temperature
probe (low resistance).
Check probe.
5.2.3. Temperature Fluctuating
Condition detected
Possible cause
Action to take
High and low
temperature alarms.
Ventilation rate too low or too erratic for proper
humidifier temperature control.
Ventilation rates below about 6 bpm or of
highly erratic nature may affect the
stability of the temperature control.
Humidifier temperature control influenced by
external heating or cooling such as air
conditioner.
Shield breathing circuit from external
influence.
Temperature probes incorrectly positioned.
Check temperature probe position in the
circuit.
Possibly faulty temperature probe
(Could be intermittent short or open circuit)
Check probe.
(Wriggle probe to pick up intermittent
faults)
