React Health (formerly 3B Medical) · Auto BiPAP
React Health Luna G3 BPAP 25A
The Luna G3 BPAP 25A (model LG3700) is React Health's auto bilevel for obstructive sleep apnea, in the same body as the Luna G3 APAP with a built-in heated humidifier, color screen and single knob. It can run CPAP, AutoCPAP, S (fixed bilevel) and AutoS (auto bilevel) up to 25 cm H2O, with your provider choosing the mode and pressures. FDA cleared the Luna G3 BPAP 25A by 510(k) in January 2021.
Specifications
| Noise | 26 dB(A) sound pressure at 10 cm H2O (uncertainty 2 dB(A)) |
|---|---|
| Power | External power adapter, 100 to 240 V AC, 50/60 Hz, with a power cord locker clip; 24 V 18 W heated tubing port |
| Weight | 1.7 kg (about 3.7 lb) per the user manual |
| Display | 3.5 inch color TFT screen with a single knob, Home button and Start/Stop button |
| Data card | SD card slot |
| Dimensions | 265 x 145 x 114 mm (about 10.4 x 5.7 x 4.5 in) |
| Humidifier | Integrated heated humidifier, about 360 mL to the max fill line; settings Off, Auto, 1 to 5; heated tubing Off, 1 to 5 |
| Connectivity | Cellular modem (listed as standard by React Health), optional Wi-Fi module, iCode and QR/QR+ codes for the React Health app, SD card; data to React Health Connect |
| Pressure range | 4 to 25 cm H2O in 0.5 cm H2O steps (CPAP, AutoCPAP, S and AutoS) |
Key features
- Four modes: CPAP, AutoCPAP, S and AutoS (auto bilevel)
- Pressure up to 25 cm H2O
- AutoS keeps a provider set IPAP to EPAP difference and raises both when it detects apneas
- RESlex exhalation relief, Off or 1 to 3
- Ramp 0 to 60 minutes
- Integrated heated humidifier with Preheat and Delay (dry-out)
- Heated tubing support
- Mask type selection and Mask Fitting Test
- Filter, tubing and mask replacement reminders
- Power cord locker that clips the adapter cable into the DC inlet
- Meets FAA RTCA DO-160 requirements for air travel
Strengths and trade-offs
Strengths
- Gives your clinician room to treat higher pressure needs, up to 25 cm H2O, which a 20 cm H2O auto CPAP cannot
- Separate inhale and exhale pressures can make high pressures easier to breathe out against
- Same simple knob menu and push-release water chamber as the G3 APAP
- Quieter rated sound level (26 dB(A)) than the G3 APAP (28 dB(A))
- Power cord locker helps stop the adapter plug from being pulled out at night
Trade-offs
- S and AutoS are not backup rate modes; the 25A does not breathe for you if you stop breathing, which is why central apnea needs a different device chosen by your doctor
- All mode and pressure settings are provider only, so comfort changes beyond the patient menu need a clinician
- React Health makes no battery or DC cord for Luna devices
- At 1.7 kg with an integrated tub it is meant for the bedside, not for carry-on travel
- Parts, repairs and error help go through your supplier, not React Health directly
Comfort settings you can change
These are in the patient menu. Your prescribed pressure and therapy mode are set by your clinician and are not covered here.
Humidifier
Moisture level: Off, Auto or 1 to 5.
How to change it: With the machine powered on and not blowing air, turn the knob until the Initial Setup icon (the last of the five icons across the top of the main screen) is highlighted, then press the knob. Turn the knob to move to the option, press it to select (the option changes color), turn to adjust, and press again to confirm. Press the Home button to go back to the main screen. The option is called Humidifier.
Preheat
Warms the water before bed; turns itself off after 30 minutes.
How to change it: With the machine powered on and not blowing air, turn the knob until the Initial Setup icon (the last of the five icons across the top of the main screen) is highlighted, then press the knob. Turn the knob to move to the option, press it to select (the option changes color), turn to adjust, and press again to confirm. Press the Home button to go back to the main screen. Set Preheat to On.
Heated Tubing
Warms the hose to cut rainout, Off or 1 to 5. Only shows when a heated tube is connected.
How to change it: With the machine powered on and not blowing air, turn the knob until the Initial Setup icon (the last of the five icons across the top of the main screen) is highlighted, then press the knob. Turn the knob to move to the option, press it to select (the option changes color), turn to adjust, and press again to confirm. Press the Home button to go back to the main screen. The option is called Heated Tubing.
Ramp
Starts at lower pressure and climbs to your prescribed pressures over the set time, in 5 minute steps or Auto.
How to change it: With the machine powered on and not blowing air, turn the knob until the Initial Setup icon (the last of the five icons across the top of the main screen) is highlighted, then press the knob. Turn the knob to move to the option, press it to select (the option changes color), turn to adjust, and press again to confirm. Press the Home button to go back to the main screen. The option is called Ramp.
RESlex
Lowers pressure as you exhale, Off or 1 to 3. The manual describes it as a feature your physician enables; if you cannot change it, ask your clinician.
How to change it: With the machine powered on and not blowing air, turn the knob until the Initial Setup icon (the last of the five icons across the top of the main screen) is highlighted, then press the knob. Turn the knob to move to the option, press it to select (the option changes color), turn to adjust, and press again to confirm. Press the Home button to go back to the main screen. The option is called Reslex.
Delay (dry-out)
Keeps air flowing at about 2 cm H2O for around 15 minutes after you stop, to dry the humidifier.
How to change it: With the machine powered on and not blowing air, turn the knob until the Initial Setup icon (the last of the five icons across the top of the main screen) is highlighted, then press the knob. Turn the knob to move to the option, press it to select (the option changes color), turn to adjust, and press again to confirm. Press the Home button to go back to the main screen. The option is called Delay.
Mask Type and Mask Fitting Test
Selects Full Face, Nasal, Pillow or Other and checks your seal with a "great" or "need to adjust" result.
How to change it: With the machine powered on and not blowing air, turn the knob until the Initial Setup icon (the last of the five icons across the top of the main screen) is highlighted, then press the knob. Turn the knob to move to the option, press it to select (the option changes color), turn to adjust, and press again to confirm. Press the Home button to go back to the main screen. Choose Mask Type, then Mask Fitting with the mask on.
Accessories reminder
Sets filter, tubing and mask reminders (30 days, 60 days, 180 days, 1 year or Off) and resets the timers.
How to change it: With the machine powered on and not blowing air, turn the knob until the Initial Setup icon (the last of the five icons across the top of the main screen) is highlighted, then press the knob. Turn the knob to move to the option, press it to select (the option changes color), turn to adjust, and press again to confirm. Press the Home button to go back to the main screen. Use Accessories Reminder and Accessories.
Cleaning and care
Replacement parts
- Tubing
- 6 ft standard or heated tubing; React Health lists Luna G3 Integrated Heated Tubing LG3HT and Ultra Noir standard tubing UN100. The manual gives tubing a 6 month expected service life.
- Filters
- Luna G3 reusable filter LG38008 (6 months) and optional disposable ultra-fine filter LG3F002 (at least every 2 weeks per the manual)
- Water chamber
- Luna G3 Replacement Water Chamber LG34510; 6 month expected service life
- Replacement notes
- React Health's resupply guide uses the Medicare schedule as of 9/27/2021: disposable filters 2 per month, reusable filter 1 per 6 months, tubing 1 per 3 months, water chamber 1 per 6 months. Order through your supplier; React Health does not sell to patients.
Troubleshooting
The machine will not start.
Check outlet, power cord, adapter and the plug in the DC inlet (the cord locker should hold it in). If the screen is stuck in standby, unplug for 20 seconds and plug back in. Still nothing: call your supplier.
The screen freezes or goes blank.
Unplug the power cord, wait 20 seconds and plug back in. Repeated freezes need your supplier.
Breathing feels out of sync with the machine.
Check for mask leak first, since leak upsets bilevel triggering; run the Mask Fitting Test. Rise time and trigger behavior are provider settings. If it keeps feeling wrong, or you feel short of breath, call your clinician rather than pushing through.
I am swallowing air and waking up bloated.
Air swallowing (aerophagia) can happen at higher pressures. Tell your clinician; do not change your pressures yourself. If it does not settle, or you have pain, see your doctor.
Rainout in the tube or mask.
Lower Humidifier, raise Heated Tubing, keep the machine below your head and use a tubing cover in a cold room.
Dry mouth or nose.
Raise the Humidifier level a step at a time. A dry mouth can mean a mouth leak; the manual suggests a chin strap or full face mask, chosen with your supplier.
Pressure feels too low at the start.
Ramp is probably running. Shorten it in the menu, or wait for it to finish. Also check the filter and the air inlet.
Air feels hot or the machine is loud.
Clean or replace the filter, clear the inlet, keep the machine 20 cm from walls and curtains, and check the tubing is fully seated.
The Wi-Fi icon is grey.
You probably do not have the optional Wi-Fi module. Ask your supplier; data can still go out by cellular, QR code or SD card.
Travel and power
React Health's August 2024 travel compliance letter lists the Luna G3 Bilevel as tested to RTCA/DO-160 Section 21, Category M, and the manual states it meets FAA requirements for all phases of air travel; carry the letter and your prescription. Bring it on board in its case, empty the water chamber first, and expect TSA to X-ray the machine out of its case. The adapter handles 100 to 240 V, 50/60 Hz. React Health does not make a battery pack or DC cord for Luna devices, so you need wall power at your destination and should not rely on aircraft seat power.
Your sleep data
Like the G3 APAP, the BPAP 25A keeps data internally and can send it by cellular modem to React Health Connect, show iCode numbers and QR+ codes for the React Health app, use an optional Wi-Fi module, and record to an SD card. React Health cannot release compliance reports to patients, so ask your supplier or clinician. OSCAR's 2.0 release notes add support for ReactHealth/BMC G3 machines and 2.1.0 adds the G3X B25A Plus; the notes do not name the LG3700 specifically, so we could not confirm that OSCAR reads every 25A SD card.
Supplies that can help
Distilled water is what most CPAP humidifier chambers are meant to be filled with, because it leaves little or no mineral scale behind.
The air inlet filter keeps dust and lint out of the machine and your airway; it is a cheap part that needs regular replacement.
Tubing with a built-in heating wire that keeps humidified air warm all the way to the mask, which is the main fix for rainout (water droplets …
The removable water tank of a CPAP humidifier; it wears and needs replacing, especially if it cracks, clouds or leaks.
A fabric sleeve that slips over CPAP tubing to insulate it, reduce condensation and make the hose feel softer against your skin.
A soft strap that supports the jaw to help keep the mouth closed, used mainly with nasal and nasal pillow masks to reduce mouth leaks.
A long, flexible brush sized to reach the full length of CPAP tubing so you can scrub the inside, not just soak it.
Plain, mild dish soap is the cleaning agent most CPAP makers and the FDA point to for masks, tubing and humidifier chambers.
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Frequently asked questions
What is the difference between the Luna G3 BPAP 25A and the Luna G3 APAP?
The BPAP 25A can deliver separate inhale and exhale pressures (S and AutoS modes) up to 25 cm H2O, while the APAP delivers one pressure up to 20 cm H2O. The body, humidifier, menu and accessories are the same. Which one you need is a prescribing decision.
Is AutoS a backup rate or ST mode?
No. React Health's manual says S mode gives no automatic breath if you do not inhale, and AutoS adjusts IPAP and EPAP when it detects apnea. React Health's separate Luna G3 Bilevel ST 30Vt (LG3800) is the S/T model with timed breaths, prescribed for different conditions.
Can I change IPAP and EPAP on my Luna G3 BPAP 25A?
No. The manual says IPAP, EPAP and the pressure difference are preset by your physician. If pressures feel too high or too low, contact your clinician; your supplier can often adjust them remotely.
Why does my 25A alarm "Leak!!"?
It alarms when leak goes over 150 L/min during therapy. Refit the mask, run the Mask Fitting Test and check both tubing ends. Persistent leak at bilevel pressures may mean you need a different cushion size or mask style, which your supplier can help with.
Does the Luna G3 BPAP 25A come with heated tubing?
React Health's product page describes heated tubing as standard on G3 models, while the manual lists it as optional in the box. Look for the tube icon turning into a number on the main screen to confirm one is connected, and ask your supplier if you do not have one.
Sources
- reacthealth.com
- reacthealth.com
- reacthealth.com
- reacthealth.com
- reacthealth.com
- reacthealth.com
- reacthealth.com
- reacthealth.com
- reacthealth.com
- api.fda.gov
- api.fda.gov
- api.fda.gov
- sleepfiles.com
Last reviewed October 11, 2026. How we research · Report an error