S9 Autoset Popping noise

[SMenasco]

The first night with my new S9 was very comfortable. However, upon exhalation, there was a slight single pop noise from the machine. It sounded to me like the operation of a pressure relief valve, possibly some type of flapper. I called the DME and they told me to turn off the EPR function, where the pressure is somewhat reduced during exhalation to decrease the exhalation against the tube pressure. I did that and it seemed to help. The next night the noise was back, after the pressures settled out. I called the DME back and they requested I bring the unit in for a check. Naturally, it would not make any noise for them. Nevertheless, they chose to replace the unit, saying that if it still made the noise, and they could not determine the origin, we might have to replace the humidifier as well. Last night, the new unit started making the same noise, just a single pop at the end of each exhalation. It also sounded like it could be a water pop, so I emptied the tank; still did it. I then disconnected the electrical connections of the ClimateLine, thinking it may be in the electrical circuitry; still did it. I then turned off the auto climate control; still did it. Then I switched it from autoset mode to straight cpap; the noise increased in volume. I then moved it back to autoset and disconnected the entire humidifier, installing the standard tubing; still did it. The noise only occurs at the end of an exhalation and at the time the noise is made, there is a slight back pressure in the hose. I am now of the opinion that it is a design feature of the unit and is some type of flapper relief valve that regulates discharge air. I can now accept it, thinking that there is nothing wrong with the unit and it is a normal noise. My question is for anyone with the S9 Autoset; does your machine make a noise similar to this? Thanks.

[Guest]

It shouldn't be making such a noise.

Have you tried it without the humidifier? Are you sure the noise is coming from the S9 and not the mask?

[apneawho]

I have not heard this noise with my machine. Let us know if you or the DME solve the mystery.

[FirefighterJim]

I had this happen 2 times after I washed my mask
It is the check valve in the mask were the hose attaches

[Perrybucsdad]

Not sure if this is it or not, but I noticed a "popping" noise with mine once before and it was rainout.... condensation buildup from the humidifier into the hose. With not being able to hear the popping you are talking about I can't say if this is it for certain or not.

What you can try is next time you hear the popping, turn the machine off, and disconnect the hose. Then, carry the hose to a sink, and see if any water drains out (make sure you don't let water drain out as you take it to the sink). Rainout is the accumulation of water in a CPAP tube due to warm moist air cooling on its way from your CPAP machine to your CPAP mask. Warm moist air leaves the heated humidifier and travels down the CPAP tube. As the air travels down the tube the room temperature can cool the tube and therefore cool the air traveling down the tube. As the air cools, the air released its moisture and condensation occurs, otherwise known as rainout.

Solutions to rainout include:

- Raising the temperature of your bedroom.
- Keep your CPAP machine at the same level as your bed.
- Insulating your tubing with a hose cover like Snugglehose.
- Purchasing a CPAP machine with a rainout reduction comfort feature (which you have so I wonder if it is working correctly).

Hope this helps.

John

[SMenasco]

Thanks for the replies. No rainout. It was on Climate Control, set at 78 degrees. And I also pulled the tubing and checked it last night. And I also completely disconnected the humidifier and connected the standard hose. I have tried about everything I can think of short of tearing into the unit. I'll just get used to it. I use a Swift II nasal pillow system, so no valves or anything else to impede theflow of air. It is definitely coming from the internal pump mechanism, just exactly like the other new machine used for one night. If some of you are using the ramp system, it may be going on after you fall asleep. I turned the ramp and the EPR back on and will check it again tonight. Thanks again. TAPERS UNITE!

[Perrybucsdad]

Does it only Pop once? The only thing (I think) you haven't swapped out is the humidifier.

[kennethryan]

Is it a gentle popping noise, or more of a snap?

I've found if I overfill my humidifier tank even a little I get a gentle popping noise if I exhale a bit hard, as the water splashes around in the tank. The tank really doesn't have any margin past the Max Fill line.

Just a thought...

[SMenasco]

I found it last niht. It is definitely a valve or flapper noise. I tured the EPR back on and set the level from 3 down to 2 and it has stopped. Thanks for all your suggestions.