I think it's best to call Miele. There are two sensors in the dryer: 1) one on the three long paddles inside the drum to read fabric moisture and, 2) one inside the exhaust plenum to monitor heat and to shutdown the unit if the exhaust gets too hot, thereby notifying you with the panel light. Either the exhaust sensor is bad, or there is something obstructing the exhaust in the machine itself. Someone earlier mentioned that they found a part, located within their 9800's exhaust, out-of-skew when they checked their unit. However, I would not mess with it, and while the Miele Tech rep is there (insist that a factory Miele tech rep. comes as they have the software, and hardware to properly work on your units) ask them to also upgrade the firmware on both your washer and dryer, if needed.

A somewhat funny story about our neighbors. He is very obsessive, VERY about everything. If directions say one thing he does that times about 4! So they'd been having dryer issues with not drying. Pulled the unit from the wall and cleaned everything, etc. Still the same issues. His wife wanted to call someone but "he just knew better" and was determined to fix it himself. So he brings in the house his leaf blower and turns it on in the dryer vent trying to "blow" the lint up the pipe and out. Guess what - didn't work. Then he went into the attic with the blower and proceeded to "blow" the vent into the house - not remembering he'd left the dryer vent off. The laundry room kitchen bedroom, etc were covered with lint dust! I just knew she was going to kill him! But it did work - except she cleaned for days and days. She said the next time she'd hiring someone when he's out of the house. True story.

Been there, done that...lint is such a HUGE annoyance to my life. We're in a 2nd floor condo where the dryer vent ducting goes to the roof through the attic over 20 feet and several elbows. My husband bought the condo years before we met, and the ducting was clogged after several years. At the time, he decided to disconnect the vent from the duct. The resulting moisture did some damage to the cabinetry (swelling of the particle board, even under layers of oil-based paint). Soon after we married, he decided we needed to fix the problem correctly. He went up into the attic and disassembled the ducting, brought it outside, and blew it out with his air compressor. I pushed some cleaning tool through it as well. We can't be doing this regularly! I mean preferably, never again! So, I had him put a filter -- a gallon paint strainer -- over the dryer vent where it connects to the machine. This clogs every month or so, we pull the machine out, disconnect the vent, clean the strainer, and put it back. This is still an annoying chore, but not the nightmare of dealing with the whole duct run. My husband had a cool idea, that what we need to do is sew a new, longer strainer that tapers to a skinny point, so that even when it clogs at the point, there can still be air flowing past the clogged strainer, and we should be able to go longer between cleanings. We got a new dryer last summer, and pulled the ducting out of the attic to clean it -- but it was already clean as a whistle. So, our secondary filter system has kept the duct run clean for 9 years. I found you can buy secondary lint traps with a door that opens to clean them out, but we don't have room to install the box in our laundry room, and I don't think it would work any better or be easier to clean than our homemade filter. When I redo the floor, I plan to put magic slider thingies under the dryer feet to make it easier to move in and out, plus I won't want to gouge my new floor. I have researched other solutions. People claim that solid metal vent will maintain better airflow than pleated, but I think it will still clog because we need 2 90-degree elbows to get it connected to the duct in the wall. And if it clogs, how do we pull out the machine with a non-stretching vent? If we could move the duct in the wall to match the dryer vent outlet, that would eliminate 2 elbows and would probably help... I also found you can install a secondary fan in the ducting near the exit, increasing the airspeed in long ducts so the lint won't clog. They cost $150-200, but if I never had to clean out the duct run or pull out the dryer to clean my makeshift secondary lint trap ever again, it would be well worth it. I also think that our ducting is leaky somewhere, because rooms on the other side of the wall (our master bath) get crusted with lint all the time. Finding and sealing those leaks would probably improve airspeed some, plus save me tons of work cleaning the lint all the time. I think the additional fan is the way to go. In 2 other areas where we replaced an ineffective low-cfm cheap fan with a high-cfm good one, like the hood over our cooktop, it made an amazing difference, night and day. Here is a link that might be useful: example of dryer duct fan

Thanks for your responses. I talked to my GC about this today and he agreed with you guys and actually had it laid out to exhaust to the side and out, about 6-7' max. The building inspector was out looking at something else and saw the layout and said it had to go straight up because it is a gas dryer, not electric. He said it had to be 25'?? feet away from a window so the only option was to be... go straight up. Anyone else have any input? Just a note. The county I live in has only had a building dept for two (2) years. Before, no inspections, no control, owner beware!! I am not sure what code they are using nor do I know what experience the inspectors have but it is possible that the exhaust of a dryer is different than the exhaust of say, a, hot water heater or gas furnace. Maybe someone with a gas dryer can respond to this in how his house is vented. Thanks Andy