Before you had it running wide open so it is fine for tonight now up to 3/4.. It wont go above 90 at less than 3/4... It is going to drop a little at night anyway because the air cools off because its only running on a percentage of power, so if you get it to 90 at 1-2pm on the Inside Glass during the day it will drop to 88 at night because the lower power wont alow it to add more power/heat to rise the temp as the air cools. Thats Fine though. So make sure not to adjust it in the evening, only do that during the day when air temps are highest/warmest.. You will have to do this again come Spring/Summer when indoor/outdoor temp rise.