The discoloration itself is only a cosmetic problem. The issue is that one of the more likely sources of the spalling is that the heating element is getting hotter than it is designed to do. That would be more than a cosmetic problem. Thanks, let's hope so. Good news is I have now received the repl...

This is all very interesting Dave, especially since your damage occoured with the dishwasher safe tub, that surprises me - be sure and keep us updated, I am curious to see what ReaMed says about your issue. Thanks, I definitely will keep you all updated, it is worrying that this is happening on the...

Julie wrote:Why haven't you seen the DME?

I'm in the UK, we don't have DME's like you do in the US & Canada. I purchased direct from ResMed.

ResMed UK say they're in discussions with ResMed Australia (head office) to discuss what is happening with the water chambers.

I thought I'd compare the difference after Night 1 and Night 5 of how the tub looks, anyone experiencing trouble with their tubs may want to take regular photos and store them just in case because it will get worse once they appear to be damaged. This is the damage caused in the AirSense 10 Humid Ai...

Thanks everyone, especially TangledHose, that really has helped, that's a great description of both with photos! Okay, now for the bad news, like I said ResMed UK ship the S9 with the dishwasher safe tub, I don't know why but I guess it's a local office/market decision to not include the standard tu...

Does anyone have a photo of what the dishwasher safe humidifier water chamber looks like? I've looked at CPAP.com and the pictures are identical for the standard vs dishwasher safer version. ResMed say they are replacing the water chamber (tub) but I'm wondering if it's like the S9. The S9 standard ...

I got my AirSense 10 on the 14th of November and didn't notice this mark until last night, (looked because of this post0. I have used every night and the mark is like the one in the photo posted by Tangled hose. Sorry to hear that but it does seem to be an inherent manufacturing defect, the good ne...

Thats what is known as thermal spalling. It's a defect in the metal caused by a hotspot that formed when that part of the metal got much, much hotter than the surrounding metal. Somehow it heated unevenly and as a result it caused this thermal spalling. This is a good indication that either the hea...

The heat cut out limit is well below water boiling temp and I think the OP said he did not run out of water in the tub......I think it's a batch of inferior metal in some of the standard tubs. They use better grade steel in the dishwasher safe tub......the standard tubs are probably made in China. ...

I showed the images to DH, who was a welder and machinist before he retired. His opinion: either very high heat, or extremely low grade stainless steel. He also asked if the tank had boiled dry. I think I'd side more with inferior metal / coating applied. I started the evening fulling the tub to ju...

Dave - I am curious about one thing in your case, can you take a flashlight and with the tub out of the machine take a close look at the heat plate itself and see what it looks like. Is there any corresponding discoloration from excessive heat on the heat plate? I'll check mine too, but I bet it's ...

Previously on the S9 I had the dishwasher safe tubs so maybe that's why I never saw a problem on the S9, but still if it's a manufacturing defect in the metal used, Resmed need to recall these or at least offer replacements if any are affected, but if it's the heater element inside the AirSense 10 t...

Thanks Guys, I can confirm night 2 there was no further damage done to the tub, looks about the same as the first night. I'm wondering whether when they adhere a metal coating or clean the meta whether its dipped in some kind of acid or chemical and maybe there were residues there that when heated u...

Ugh, that last post came out as guest, seemed to log me out. Anyway thanks guys, will get onto Resmed on Monday when they're back.

I've been using tap water for 9+ years without a problem in the H4i and H5i without a problem, so I know its nothing to do with my water supply and more to do with the water tub in question. Even after 1 night use unless you're putting acid in there, it shouldn't go like that after a single use. EDI...