So I got all new sweet thermostats because the dial type ones I had just didn't seem to be very accurate (they had been working fine, but I came into some cash and wanted to upgrade). I placed the probe between the tub and the heat tape and set it to 90, after a while I was just getting tub temps in the upper 70s low 80s so I raised it to 95....which resulted in tub temps (taken by infrared) of about 83-85 after 48 hours of letting the heat 'settle in'. In order to get tub temps up to 90 I'm thinking I'm going to have to up the thermostat up to 100. I have a belly heat pvc rack system with two strips of 4 inch heat tape.

Do you find that you have to up your heat tape in order to get a good in tub hot spot? With the dial system I kinda just turned the dial up and up until I got a 90 hot spot...but that never really told me how hot the tape itself was.

Just making sure that I'm not crazy. It makes me nervous to see 100 on the thermostat even though I'm checking tubs at 95 on the heat tape and not finding any 95 degree hot spots, not even any 90 degree ones.