Rent break for waiting on repairman?

Future-Proof: Navigate Threats, Seize Opportunities at ICNY 2018 | Jan 22-26 at the Marriott Marquis, Times Square, New York

Q: A tenant who rents a house from me is requesting that I allow her to deduct lost wages from her rent. She notified me that her air conditioner was not working properly. I immediately called the home warranty company who sent out a technician as soon as it could that same day.

(The technician) made the repair, but the air conditioner began malfunctioning again shortly after he left. I then called an air conditioner repair company who came out and replaced another malfunctioning part the next day. I responded as quickly as was humanly possible.

On the first of the month, the tenant sent me a letter with two checks enclosed. One check was for the full amount of the rent -- $850 -- and a second check for $755. She said that she was sending both checks and would "let me decide which one to cash." She said she lost work waiting for the technician to make the repairs.

I believe I did everything I could to ef...