Do you have a thermostat for That uth? If you do maybe your probe is in the wrong spot. It should be on the floor of the tub on the hot spot. The whole tub shouldn't be 92.f the hot spot should. If your ambient temps are 80 that's fine. Even using tubs the hot side should be 90-92f and the cool end 80-85.f. It was Warmer in the summer for the obvious hot weather. But it also could have been too hot at times. If you don't have a thermostat with that uth you run the risk of over heats, death, and thermal Burns. I've seen uth's melt tubs all together. Hope this helps.
Morgan