How To Operate a Homefill System

by Justin LaClair January 04, 2021 5 min read

Congratulations on the purchase of your Invacare Homefill system! This system will allow you to fill your own Homefill specific oxygen cylinders whenever you want to. No more waiting on your local home care company to deliver your cylinders. You regain your freedom and mobility!

The Invacare Homefill system is made of 3 major components. The first major component is the Oxygen Concentrator. The second component is the Homefill pump. The third component is the Oxygen Cylinder. Here we will discuss the components and what their task is.

Oxygen Concentrator

Typically you will see the Invacare Platinum 5 or 10LPM oxygen concentrator, or the lightweight Invacare Perfecto 5LPM oxygen concentrator used in the system. An Oxygen Concentrators job is to pull in the air from the room around it, filter out the nitrogen, and pass the high purity oxygen to the patient. The sole purpose of the oxygen concentrator for a homefill system is to produce high purity oxygen to provide to the Invacare Homefill pump. Depending on the oxygen concentrator you are using, you should be able to breathe off of the concentrator as it is filling the oxygen cylinder. More on that later.

Homefill Pump

The second major component is the Invacare Homefill pump. The purpose of this pump is to take the high purity oxygen from the Oxygen Concentrator, and squeeze it into your oxygen cylinder. The Homefill pump has an internal rotary pump that is comprised of 5 cylinders. The cylinders are numbered "stage 1" through "stage 5". Stage 1 is the largest cylinder, and the lowest pressure. As the oxygen passes from cylinder 1 through 5, the physical cylinder size gets smaller, which allows the output pressure to increase. By the time the oxygen passes through stage 5, in to your oxygen cylinder, once the cylinder is full, the Homefill Pump will automatically shut off when the cylinder reaches 2000 internal PSI.

The homefill pump has a safety switch to shut off at 2000 PSI as to not overfill the tank. If the switch were to fail, do not worry! There is an internal pressure relief valve built in. If the internal pressure reaches an unsafe amount, the pressure relief will engage and release all built up pressure as to avoid catestrophic failure, and harm to the user.

Oxygen Cylinder

The last major component is the Oxygen Cylinder. Homefill compatible oxygen cylinders are manufactured with a special fitting installed. This fitting is necessary to connect to the Homefill Pump. Any old standard oxygen cylinder will NOT work with the homefill pump, and generally can not be retrofit. There are aftermarket adapters made for that purpose. The cylinder simply clicks into the adapter on the homefill pump. Make sure that your tank valve is closed while filling, or it will never fill!!!

Now that we know the components, here is how they work. It can be a little confusing, but if you read closely, this may help you troubleshoot your system, and understand its operation better.

Oxygen Concentrator Indicator. Invacare calls it "SenseO2". Most oygen concentrators have this option. Its a green "O2" light on the front of your machine that is illuminated once your oxygen concentrator is producing an acceptable purity of at least 85% pure oxygen, or higher. Please keep in mind that the higher LPM your machine is set to, the lower the purity will be. In a new machine, it may run 91% at 5LPM, and 96% at 1LPM. These differences get exaggerated as the machine ages and wears out. We have seen some machines running at 80% at 5LPM and 85% at 1LPM. The machine will put out "acceptable" purity at 1LPM, but barely. The purity light is not always the best gauge of your concentrators health.

Your homefill pump has a built in purity sensor as well. It is designed to not turn on the pump and start filling your tanks until it reads the incoming oxygen from your concentrator being AT LEAST 91% purity. This is where it gets confusing, so please pay close attention.

How the Homefill Works Together

While operating, the homefill compressor demands 2LPM of oxygen from your oxygen concentrator. This means that the concentrator can provide UP TO 3LPM of oxygen out of the front outlet, for the patient to breathe on at the same time. 2LPM to the compressor plus 3LPM to the patient means a total of 5LPM total capacity, which is what the oygen concentrator was designed to deliver. In theory, this works. However, as described above, if your concentrator has some age on it, and is not working its best, it may give you some weird symptoms. Lets say that your oxygen concentrator tests at 90% purity at 5LPM. This is decent purity, not the best. Your concentrator is operating at manufacturers specifications and the normal green "O2" light will be illuminated, indicating everything is fine, which it is. The issue is when you try to fill a bottle. When you turn the front flow meter down to 3LPM to breathe while filling, and 2LPM will be going to the pump to fill your cylinder. Remember, the oxygen concentrator was operating at 90% at 5LPM in our prior test, which is not enough purity to start your homefill pump....but the oxygen concentrator still tell you everything is fine! This situation would typically show a yellow "Low Oxygen" light on your homefill pump. In this situation, your machine will need some repairs or tweaks to get your purity up to the minimum amount necessary.  This is a worst case scenario. As most patients typically use 2LPM of oxygen, and 2LPM will go to the pump, the concentrator will only be running at a capacity of 4LPM. I am willing to bet that the purity will increase to the minimum necessary for this scenario. If you are NOT breathing off of the concentrator while filling, we always suggest to run the concentrator at 1LPM to allow maximum purity to be filled into your bottles.

Homefill Troubleshooting

As discussed above, if you have the "Low Oxygen" light illuminated on your homefill pump, you will possibly need repairs of your oxygen concentrator to increase the output purity so the homefill pump will operate properly.

If you experience the pump cycling on and off, while the control panel lights switch from "Low O2" to "Filling" back and forth, that generally indicates an air leak somewhere. Check your transfer hose tubing connections with soapy water and inspect for bubbles. Your hose may need replacement. Also, the connection on your concentrator or homefill pump may also be failing and leaking internally. This repair is not difficult, but may need to be carried out by a trained technician if you are not mechanically inclined.

If your homefill pump says "filling" as per usual but your tank never seems to get full, you may have a leak. Make sure your tank is closed, first off. Next, make sure the tank fitting is properly seated in the receptacle on the pump. If all is secure, it may be that your pump has developed an internal leak after years of service. The only way to fix this is to have your pump diagnosed and repaired.

We hope this blog has helped educate you on its operation, or maybe even helped diagnose an issue! If you have any further questions you can email is direct to or feel free to reach out to us using the chat app on our website!

Justin LaClair
Justin LaClair

Justin has been working with OxygenPlus since their storefront start in 1993. In 2002 he earned the title of CEO and has been operating OxygenPlus ever since. Most of the time if you call, Justin will answer the phone. He tries to be extremely hands on with most every transaction that takes place. Raised with a very high quality standard, any work must meet his satisfaction before it is approved. He is a classic car enthusiast, loves traveling either for work or pleasure, and is a renewable energy advocate. As of 2015, he saw to it that his personal home, and OxygenPlus Medical run 100% off of solar power.

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