I do control it with thermostat. I have two on each side with two thermostats. yesterday temps were perfect (89-94 and 80-84) until I noticed today that the cool side was 72F. I checked the UTH and it was cold.

I have a 32qt tub. Would it be okay if I blocked off half of it and forced the bp to only stay on the warm side until I get something else for the other side?