Humidification systems · Precision Flow family

Vapotherm Precision Flow Plus: troubleshooting and error codes

The ServiceForge knowledge base holds 14 documented symptoms for the Vapotherm Precision Flow Plus, with 20 ranked causes, 2 diagnostic checks with test points and expected values, and 17 error codes. Each symptom below shows its causes and the first check; the rest is one connection away. Connect ServiceForge to your AI

Symptoms

O2 sensor fault with display dashes patient safety

General fault icon flashing, % O2 displays dashes (--), medium priority audio signal, cannot be muted

Ranked causes

1. Depleted or defective O2 sensor (common)
2. Bad 3-way solenoid valve (occasional)
3. Bad O2 sensor wire harness (occasional)

3 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Water out alarm patient safety

Water out icon flashing, medium priority audio signal, no water in Disposable Water Path, gas flow continues without heating or circulation

Ranked causes

1. Sterile water empty (common)
2. Obstructed inlet tube (occasional)
3. Faulty DPC water float or water level sensor (occasional)

3 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Blocked tube alarm patient safety

Blocked tube icon flashing, medium priority audio signal, mutes only during brief reset period, gas flow continues

Ranked causes

1. Obstructed or kinked cannula or delivery tube (common)
2. DPC not fully seated (occasional)

2 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Disposable Water Path faulty or not detected patient safety

DWP icon flashing, medium priority audio signal, unit will not run

Ranked causes

1. DPC not assembled, defective, not properly seated, or not installed (common)
2. Faulty stator motor (water pump) (occasional)

2 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Battery mode operation patient safety

Battery charging icon flashing, medium priority audio signal, unit running on internal backup battery, gas flow and blending continue without heat or circulation

Ranked causes

1. AC power disconnected (common)

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Cartridge fault detected patient safety

Cartridge alarm icon flashing, medium priority audio signal, cartridge not detected, unit will not run

Ranked causes

1. Faulty sensor or cartridge not detected (common)

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Gas bubbles in water circulation patient safety

Cartridge fault icon continuous (not flashing), low priority audio signal, unit continues to operate

Ranked causes

1. Excessive gas diffusion or DPC not fully primed (occasional)

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Gas supply pressure out of range caution

Gas supply icon flashing, medium priority audio signal, gas supply pressure outside 4–85 psi (28–586 kPa) range

Ranked causes

1. Gas supply disconnected or exhausted (common)

First check

Verify gas supply pressure within operating range

Test point: Gas inlet
Expected: 40–85 psi (optimal 55±10 psi), ±10 psi

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

General fault alarm triggered patient safety

Flashing icon on LED panel, medium priority audio signal (rapid triple beeps), cannot be muted

Ranked causes

1. Sensor or control system malfunction; internal component failure (unknown)

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

General fault with dashes and temperature out of range patient safety

General fault icon flashing, % O2 and L/min display dashes (--), temp displays 52–84°C, medium priority cannot be muted

Ranked causes

1. System control failure (unknown)

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Selected flow cannot be provided caution

Gas supply icon continuous and flow rate parameter display flashes, lowers in value, medium priority audio signal

Ranked causes

1. Inlet gas pressure too low for selected flow rate (common)

First check

Verify gas supply pressure sufficient for selected flow

Test point: Gas inlet pressure gauge
Expected: 40–85 psi minimum; optimal 55±10 psi, ±10 psi

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Temperature flashing above setpoint caution

Temperature parameter display flashes, temperature at least 2°C above set point

Ranked causes

1. User entered setpoint much lower than previous temperature (common)

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Temperature flashing below setpoint caution

Temperature parameter display flashes, temperature at least 2°C below set point

Ranked causes

1. Low water temperature or new water bag with low initial temperature (occasional)

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Temperature out of range patient safety

Temperature display shows two dashes flashing, general fault icon, medium priority cannot be muted, unit will not operate

Ranked causes

1. Overheating or temperature sensor malfunction (unknown)

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Error codes

Code	Meaning	Trigger	Severity
`52`	Pressure sensor 1 (AIR) out of range	Air pressure sensor reading exceeds operating range	error
`53`	Pressure sensor 2 (O2) out of range	O2 pressure sensor reading exceeds operating range	error
`54`	Mass flow sensor 1 (AIR) out of range	Air mass flow sensor malfunction	error
`55`	Mass flow sensor 2 (O2) out of range	O2 mass flow sensor malfunction	error
`57`	PS4 back pressure out of range	Back pressure sensor 4 reading exceeds operating range	error
`58`	O2 sensor disconnect – unit will not start	O2 sensor is not connected or not present	critical
`59`	Pump tachometer out of range	Water pump motor speed sensor reading out of range	error
`61`	Battery voltage below range	Internal backup battery voltage drops below minimum operating level	warning
`63`	POST test failure	Power-on self-test routine failed during startup	critical
`64`	Spurious reset; Battery voltage below range	Unexpected system reset with low battery voltage	warning
`65`	Watchdog timer failed	System watchdog timer did not respond correctly	critical
`67`	Post RAM test failed	RAM memory test failed during power-on self-test	critical
`68`	Flash memory corrupt	Flash memory integrity check failed	critical
`77`	Heater thermocouple failure	Temperature measurement circuit failure	error
`78`	IR sensor TS1 failure or disconnected	Infrared temperature sensor 1 not responding	error
`79`	IR sensor TS2 failure or disconnected	Infrared temperature sensor 2 not responding	error
`84`	SW or hardware inconsistency	Software and hardware configuration mismatch detected	error

Likely causes and actions for each code are in ServiceForge. Connect ServiceForge to your AI

Community

0 fixes logged by technicians through their AI, with outcomes, for this model.

ServiceForge knowledge base record. Field-unverified unless technicians confirmed it. A teaching summary of the record, not a service manual. Export 2026-10-14.