Tenant Keeps complaining it is too cold, even after 74

[Kawsar Ali]

We just recently moved into to a new house we purchased 2 months ago and a new tenant moved in on the 2nd floor on the 5th last month. For past the two weeks or so she has been driving me insane about the heat. By NY Law I am suppose to keep it at 68. After her complaining I bought it up to 74 degrees. I live on the 1st floor and have the thermostat in my living room and it is programmable. One or two nights she called 2 o clock at night to turn on the heat. This morning she called me at work to turn up the heat. She was saying how on the other places she did not have this problem. I even showed her the thermostat schedule The 1st room is a bit cold which I told her I understand and she said she would put two blinds and I gave her window sealer which I bought. I told her to get tape to cover the window for any draft she did not. I pay for the heat. Any advice would be helpful. My boiler is bit old have plan to replace this summer. By reading this forum I realized I need to check all the radiator bulbs. I will go and inspect the rooms today to see if its cold. What would be mature and fair response. I was tenant myself before and I did not complain this much.