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GoodKnight 425 ST Bilevel Machine

BY Puritan Bennett  |  Item #Y-GK425ST

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Item # Y-GK425ST

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Overview of CPAP DC Cables and Batteries
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GoodKnight 425 ST BiLevel Machine

The GoodKnight 425ST BiLevel machine is everything you need to monitor therapy effectiveness and comes with new FlowSens Technology. Designed for both daily use or small enough to travel, the 425ST has a Backup Rate that helps manage breathing. The FlowSens technology, Backup Rate and software are the most complete solution on the market for treating sleep apnea.

CPAP.com does not currently sell any BiPAP ST Machines, so we can't recommend an equivalent machine at this time.

GoodKnight 425 ST BiLevel Machine

The GoodKnight 425ST BiLevel machine is everything you need to monitor therapy effectiveness and comes with new FlowSens Technology. Designed for both daily use or small enough to travel, the 425ST has a Backup Rate that helps manage breathing. The FlowSens technology, Backup Rate and software are the most complete solution on the market for treating sleep apnea.

CPAP.com does not currently sell any BiPAP ST Machines, so we can't recommend an equivalent machine at this time.

Learn More About Your New Machine

This is a BiLevel machine which differs from a CPAP in that it switches back and forth between two pressure levels, one higher and one lower, rather than providing one continuous pressure level. The pressure upon inhalation is higher to hold the airway open, but as the user exhales, the pressure drops to a preset lower level. The GoodKnight 425ST BiLevel comes with FlowSens technology that helps optimize therapy effectiveness through controlled breathing. By allowing CPAP users to set the device's sensitivity, the flow-based detection system compares CPAP user data with a delayed air flow to trigger inhalation and exhalation breaths. The FlowSens technology provide a unique custom device can compensate air flow on a breath-by-breath basis.

A BiLevel machine responds well to people with very high CPAP pressure needs, weak chest wall muscles, lung disease or other health problems that keep them from being able to exhale against a CPAP pressure. The Puritan Bennett GoodKnight 425ST model comes with a Backup Rate that will initiate a cycling process of exhalation to inhalation if the CPAP user's breathing rate falls below the prescribed ratio.

  • Smallest, lightest Bilevel, BiPAP or VPAP
  • SilverLining software compatible
  • International power supply
  • Direct DC operation
  • Automatic altitude compensation
  • Two washable, reusable pollen filters
  • 2 year manufacturer warranty against defects.

Sound Level: 31 dB

Machine Dimensions: 5.6 in L x 2.9 in W x 7.7 in H

Machine Weight: 1.6

Machine Warranty: 2 Years

Default Machine Settings: 3-25cm H2O

Humidification Available: Yes

Humidification Type: Integrated

Ramp Mode: Yes

DC Capable: Yes

Battery Option: Yes

Auto Altitude Adjustment: Yes

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CPAP.com always offers these services

  • 24 hour access to our CPAPtalk.com Support Forum
  • Learning Center for information on sleep apnea and cpap equipment
  • Consumer Purchasing Trends Reports
  • Warranty Services for all items purchased through CPAP.com
  • Insurance Compliant Invoices
  • Free Prescription Request System

BiLevel is the generic term to describe these machines. BiPAP is registered with Respironics, ResMed uses VPAP, and Bi-Level is registered with Covidien.

The 12 volt jack on this machine is not the same size as the 420 series CPAP machines. Use the Respironics "12volt DC Power Cord (to connect CPAP to cigarette lighter socket)" for battery operations. Part # 1001956.

Error Note: If the machine displays an error 7 or "ER 7" this indicates an issue internally with the machine's blower. You can contact the provider of the machine to seek service if it is available, or the machine may need to be replaced.

cpaptalk.com 425 Bi-Level Interview

Manufacturer Warranty
This machine comes with a 2 Year Manufacturer Warranty. CPAP.com will work with the manufacturer on your behalf if the machine needs repairs. Please follow these steps:

  • Contact us at cpap@cpap.com or 1-800-356-5221 to receive an RMA (Return Merchandise Authorization) Number before returning the equipment
  • Include a note with the machine describing the issue you are experiencing, along with your full contact information to include a return shipping address and the RMA number provided to you
  • Ship only the defective items to CPAP.com at 10101 Stafford Centre Drive, Stafford, TX 77477
  • Do not return accessory items such as the carry bag, hose or power cords
  • Email updates will be sent to keep you informed as the machine moves through the warranty process
  • CPAP.com will contact the manufacturer on your behalf and handle all shipping between us and the manufacturer
  • The repaired or replaced unit will be returned to you. Shipping charges may apply.

Please note: The manufacturer warranty is voided by water damage or misuse of the machine.

360
Universal Power

This system operates automatically between 110v and 240v AC. When traveling either inside or outside the USA, there are no switches to switch or fuses to change. The machine will automatically sense what voltage is needed and set itself to run on that power.

The user will need to adapt the plug that goes into the wall to fit the style of outlet socket that is being used. This is simply done with a Power Adapter Plug kit. This is the same type of plug adapter that would be used with a hair dryer or an electric shaver. World Traveler Power Adapter Plugs.

Universal 12 Volt DC Power Cord

This machine come equipped with a DC plug on the back of the unit. This allows the user to connect the CPAP to an external DC battery source. The IntelliPAP can be powered by plugging the 12volt DC Power Cord into a cigarette lighter plug. This is ideal for traveling by car, boat, or recreational vehicle that is equipped with a cigarette lighter plug.

CPAP.com Battery Kit with Universal 12 Volt DC Cable

The 2.5 lb CPAP.com Battery Pack is surprisingly small and lightweight. The lithium ion battery can be recharged at any discharge level without losing charge time due to battery memory loss. This battery has been approved by the United Nations and Department of Transportation as tested safe for travel. This battery kit comes with the CPAP.com battery and the 12 Volt DC Power Cord.

Respironics Battery Kit with Universal 12 Volt DC Cable

This portable battery pack is an external lead acid battery that is the ultimate in power, portability and convenience. This battery kit comes with the Respironics battery and the 12 Volt DC Power Cord (connects CPAP to cigarette lighter socket).
What does CPAP therapy do?
CPAP therapy provides a constant airflow which holds the airway open so that uninterrupted breathing is maintained during sleep. It is traditionally provided through a nasal mask that seals around the nose to maintain the pressure level.
Which CPAP masks work on which machines?

Any mask will work with any machine, with one important exception. The ResMed AirMini is only compatible with certain ResMed CPAP masks. Compatible masks for the AirMini are as follows:

  • ResMed AirFit™ N20 Nasal Mask
  • ResMed AirFit™ F20 Full Face
  • ResMed AirTouch™ F20 Full Face
  • ResMed AirFit™ P10 Nasal Pillow

When considering another CPAP, APAP or BiPAP machine from ResMed or any other manufacturer, mask compatibility extends to all brands. The AirMini uses non-standard tubing to connect the machine to the mask, and is the primary reason why other masks won't work with the AirMini. Despite this issue, many of our customers consider the AirMini to be an excellent machine.

How do I choose the machine that is right for me?
We provide our customers with many tools to make informed decisions about their machine purchases. Options include:
How can I compare different machines?
We work very hard to provide many different ways for our customers to compare products. Here are the machine product guides we have created and maintain:
  • CPAP Machine Comparison Guide. This guide stacks up every CPAP machine we sell, feature by feature. If you don't know the meaning of a feature, click the question mark for a definition. The links below will take you to the most popular CPAPs, or all CPAP machines we sell.

    Compare Most Popular CPAP Machines

    Compare All CPAP Machines

  • Auto Adjusting Machine (APAP) Comparison Guide. This guide stacks up every APAP machine we sell, feature by feature. If you don't know the meaning of a feature, click the question mark for a definition. The links below will take you to the most popular APAPs, or all APAP machines we sell.

    Compare Most Popular APAP Machines

    Compare All APAP Machines

  • BiPAP, VPAP and BiLevel Comparison Guide. This guide stacks up every BiPAP machine we sell, feature by feature. If you don't know the meaning of a feature, click the question mark for a definition. The links below will take you to the most popular BiPAPs, or all BiPAP machines we sell.

    Compare Most Popular BiPAP Machines

    Compare All BiPAP Machines
What comes with my machine?
Machines come with a six foot hose, power cord, at least one filter, and manuals. Most manufacturers include a carrying case which is designed specifically for their equipment. CPAP, APAP, and BiPAP machines do not come with a delivery system or mask. CPAP masks must be purchased separately.

To see the list of what specifically comes with each machine, you can Browse for a machine. Then on the product page, click the "Specs" tab to see a full list of what comes with the machine.

Do all CPAPs use filters?
Yes, all CPAPs use at least one filter that is usually a type of foam material and washable. Some CPAPs offer finer filtration with the addition of a disposable paper filter.

Cleaning and changing filters is the only maintenance required for a CPAP machine.

The filters are located at the back of the machine at the air intake.
Are prescriptions required for mask, machine, humidifier, and EPAP purchases?

Yes. Federal law requires we have a valid prescription on file before we ship your mask, machine, humidifier, or EPAP therapy, including Provent and Bongo RX. You will also need a prescription to purchase the Nightbalance POSA device.


We provide many easy ways to get your prescription:

  • We can request your prescription for you! When you checkout, just let us know you would like us to request your prescription, or you can log into your account to have us request your prescription.
  • Fax your prescription to our toll-free fax number: 866.353.2727, or our international fax number: 713.541.7377
  • Email your prescription to cpap@cpap.com
  • Upload your prescription in your account, under the Prescriptions Section
  • Ask your doctor to fill out our prescription form. We have both a standard prescription form and an EPAP prescription form.


For more information on prescriptions, please see our Prescription Section of the Learning Center.


What is ramp?
The ramp button on a machine is a feature that allows for a gradual pressure build-up to your prescribed pressure. The feature is enjoyed by those with high pressures because it eases up to their pressure.
What is exhalation relief?
Exhalation relief is a comfort feature which reduces the air flow at the time of exhalation, making the breathing process more natural.

The following are the different types of exhalation relief names by manufacturer.

  • Philips Respironics = C-Flex, C-Flex+, A-Flex and Bi-Flex
  • Resmed = EPR (Expiratory Pressure Relief)
  • 3B Medical = RESlex
  • Apex Medical = PVA (Pressure Variation Algorithm) Pressure Relief
  • Curative Medical = EUT (Expiratory Unloading Technology)
  • DeVilbiss = SmartFlex
  • Fisher & Paykel = SensAwake Technology
  • Human Design Medical = Z-Breathe
  • Somnetics = EZEX

Here are some machines with an exhalation relief feature:

Transcend Auto miniCPAP™ Machine with EZEX
PR System One REMStar 60 Series Auto with Bluetooth
AirSense™ 10 AutoSet CPAP Machine with HumidAir™ Heated Humidifier
+ See More
What maintenance is required on machines?
The only care a CPAP, APAP or BiPAP machine requires is to clean or change the filters at the air intake. This keeps the internal parts from accumulating dust. Fine paper filters should be changed out every 30 days, or when they appear soiled. Foam washable filters should be rinsed with clear running water once a week, allowed to air dry, and reinserted.

Here are some other suggested actions to care for your machine:
  • Keep the area around your machine clean by removing any dust from the area to improve the air quality delivered to your machine and to you.
  • Keep the air intake of the machine unblocked. Curtains, bedding, and papers can easily block the air intake of your machine, reducing the airflow.
  • If a humidifier is used with your therapy, do not pick up the machine with the humidifier attached. With most machines it is easy to spill water from the humidifier chamber into the machine causing damage. Manufacturer warranties are voided by water damage to the machine. To avoid this, remove the chamber from the humidifier and then remove the humidifier from the machine rather than transporting them together.
  • If a humidifier is used, empty the water from the chamber every morning. Accidents happen. If a family pet or family member moves the machine and humidifier with water in the chamber it is more likely that water could be spilled into your machine. Water damage to a machine voids the manufacturer warranty.

CPAP.com 100% Price Protection Guarantee

When you shop with us, we want you to be confident that you are receiving the best available price. If this items goes on sale or you spot an online or retail competitor with a lower price within seven days of your purchase, let us know, and we will credit you the difference.

"Super helpful, fast shipping, friendly assistance, great selection, I love this company."

- Verified Customer, 10/25/22

★★★★★

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Compare Similar Products

Manufacturer
Puritan Bennett
ResMed
ResMed
Warranty
2 Years
2 Years
Sound Level
31 dB
26.6 dBA
Quiet
-
-
Yes

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