They were sent out to us by our home warranty service, which should have been my first red flag since our home warranty has been terrible.  There was a $60 service fee for them to come out.  They said that the issue wouldn't be covered by our home warranty, but they would fix it for $30, so we would owe a total of $90.  We confirmed with the service guy three times.  We paid the $90 in cash, then got a bill later from our home warranty for an additional $60.  Air Pro Master then said the repair was $90 and we still owed the $60.  From now on, don't trust anything that comes out of their mouth, make sure it is crystal clear in writing.