Pop the top miele t9820 dryer gas

Page 58 of the service manual says 'No Gas Ignition'. You need a service call as it is GAS appliance.

https://www.slideshare.net/avermapub/miele-gas-dryer-t9820-service-manual

I couldn't find anything in normal searches. Code 98 is specific to that model.

https://www.google.com/search?q=miele+dryer+error+code+98+fix

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did you get your software update done during the campaign? Call miele for the software update. while the tech is there, ask him any question you want. it is free of charge, and it is a safety issue on that dryer. 800 999 1360. dsc software update.

disconnect your duct from it temporarily. see if the grinding noise goes away. Some installers are using the foil flex duct on these dryers and it makes a horrible noise. it sounds like marbles rattleing in a coffee can. It is called cavitation. it should be connected with semi ridgid 4 inch ducting, that comes in 3 foot sticks, not the slinky looking stuff that comes in a small box.
to remove the lid, take a dental pick or a sharp knife, pry out the two oval plugs on each side of the lid to expose the t 20 lid screws. loosen each screw 10 turns and push in on the screws. this will disconnect the hidden clamps. do not remove the screws. you will drop the clamps in the bottom of the dryer. you have been warned. if the lid will not lift up after 10 turns, go another turn or two, but check often by lifting the lid. when you have released the clamps enough, lift the lid up and push it back towards the wall three inches. now remove the lid.

I had the same problem with my dryer. The Miele technician came and took a look at it. There was nothing wrong with any parts. My vent pipe was kind of crumbling, so he replaced that. He then scrubbed and washed the lint filter with dishwasher soap and
the green scrubber, He also did a PC update of the firmware. My
unit already had the latest version, but he did erase all the error codes.

After all these rather simple steps the dryer started working like a charm.

He said the most probable caused was gummed lint filter because of using the dryer sheets. Miele dryers are designed to prevent static cling and he advised not use these sheets as they contain wax-like substance.

I would suggest scrub cleaning the lint filter first and see if that helps.

check out my tips on dryers
the tensioner and belt needs to be replaced more than likely

Call Miele and schedule a PC update. When the technician comes he will do the update, if needed, and will reset the error codes.

Don't mess with it. Call Miele. The front seal is probably worn and caused the belt to break.

Check the drive belt. Pop the top (spring loaded) to check. If broken, remove the front panel for full access.

Thanks for your quesiton

you have probably blown your thermostat especially if your condenser is blocked and hasn't been cleaned. this causes the unit to over heat and to protect the heater element the thermostat blows and breaks the electrical circuit. you will need a Miele service tech or service agent to repair the unit.

Contact Miele 1800-999-1360 for a new blower fan