My sister doesn't respect the indoor temps

My sister and her boyfriend got into a big fight and she asked if she could come to stay at my house for a couple of days.

I knew that my sister and her boyfriend were having a lot of problems and one time I thought that her boyfriend might have given her a black eye. I was happy that my sister was finally going to leave so I said that it fantastic if she wanted to come to stay in my house for a couple of days. That was 3 weeks ago and my sister is still at my apartment. I asked my sister every couple of days when she was planning to leave and go back to her place. She told me that her boyfriend is still there and she cannot make him leave. I do not know if that is true or not, because I do not know if her boyfriend’s name is on the lease. They weren’t together when my sister moved into the site, even though I know that they have been together for at least 8 months of the lease. I know that at some point my sister added him to the paperwork. I tried to get my sister to move to my mom’s house after we got into a confrontation about the indoor temperatures in my apartment. I’m not charging my sister anything to live with me temporarily, so I want her to follow my rules. I like to keep the thermostat set at 78° in order to keep the electric bill under $200 every month. My sister prefers to turn the thermostat down every time I leave the house. She is getting on my nerves.

heating repair