I have a 20 gal L setup that had a Zoo med UTH on one side so I decided to use it instead of swapping it out. I have it hooked to my Herpstat 2 and have it set on 90 (I have the probe on the glass in the tank so it is on the surface the snake can come in contact with.

For some reason this will heat up to 89.7 and the Herpstat will shut power to it and it will continue to climb to 93.5 on a consistent basis. Any one else have any issues like this?

I have another set up basically the set the same way on the other side of the stat and it never goes above 90.7.

Just curious if it is just a zoo med climb rate thing or if something else is going on.

Thanks