Dear Landlord,
A dryer which works seven times out of 10 and swallows your money the other three times does not count as "working." If I showed up to work only seven days out of 10, I would not have a job. We can have a protracted back and forth about whether it works or not, you can pretend you're going to fix it and do nothing, or you can simply replace it. You may find you are able to pay for it out of the $100 rent increase you have implemented on all new leases across your 12 units in the building.
Sincerely,
A Guy with a Limited Supply of Quarters Who Enjoys Dry Clothes