ResMed S9 whistle problem - Solutions?

[Airstream]

For what it's worth, my S9 has had that slight whistle since day one (over 2 years). It does it on exhale. I think all S9's do this. I was on a Respronics BIPAP before that and it was loud! I use regular tubing and a Quattro and I think the entire system is exceptionally quiet. My wife is very sensitive about having quiet so she can go to sleep and found the whistle tolerable. My alarm clock ticking on the nightstand is actually louder than the S9. /Jeff/

[zonk]

Paula
My machine serial number start with 2210

22= country of manufacture: Australia (23 Singapore)
10= year of manufacture: 2010

[PaulaO2]

Good. I'll look at mine tomorrow (well, today). It would be interesting to see if the whistling ones were made in the same year or were scattered about. Same year would mean bad batch of parts. Scattered about would mean just random wonkiness.

[Airstream]

You can put me down as a 2210 as well. I just checked. /Jeff/

[cincysinner]

I'm a 2212

[SuperSleeper]

Mine is 2209 (Manufactured 2009 in Australia).

It's a early model, but I'm still glad it's an Aussie machine and not made by Singaporians.

Oh, and no whistle as far as I can tell, but both mine and my wife's hearing is not top-notch, so who knows...

[PaulaO2]

Both my Escape and Autoset say 2210.

The Escape had the whistle, the Autoset does not.

[Shastzi]

2312 and this Autoset also has the whistling disease.
Just mildly annoying.

[jgjones1972]

Mine is also a 2312 and only makes the noise under the conditions I described before.

[HILLTOPPER]

After reading this thread the other day I payed attention .. Seems My res med s makes WAY more whistle when the water chamber is FULL , not much at all when almost empty and only on Exhale. Go figgure?