Here is the item again:
Although fans blew in every room,
(A) Faye
found the house unbearably hot.
(B) And wished
that the air conditioning repairman,
(C) who was
already three hours late, would pull into her driveway.
You correctly realized that the period after hot created a problem. And wished that ... is a lonely verb fragment, so it cannot stand alone as a complete sentence.
To fix this fragment, you chose to do this:
Although fans blew in every room, Faye found
the house unbearably hot and wished that the
air conditioning repairman, who was already
three hours late, would pull into her driveway.
You have correctly employed Punctuation Rule 8:
Main Clause + Ø + Lonely Verb.
Rock on!