Do you have attached neighbors? We are in a townhome and if it is not AC weather even if we turn all the heat off the top floor never gets below 80 no matter the temp outside so I am sleeping with windows open at 20 degrees so we don't suffocate in a 100 degree room. I suspect it is due to flawed venting where all the heat from the other units collects under the roof. Bottom floor is always freezing. The heating units are on the top floor which ignores the benefit of physics completely where if you put heat producing units on the bottom floor it naturally rises and heats the space as it moves up, like it does :/