Give it a couple hours. Check it again. Then up your thermostat a couple degrees and repeat.
The surface temperature is what you want, not what your thermostat is set at.
Ok, thank you. The glass directly is reading at about 85 towards the center of the uth. What would be ideal? Around 90 or so?
If an on/off thermostat I would got about 90-91, proportional would be about 93.
Ok, it regulated out. Glass above UTH is reading in at 93 degrees. Thermostat had to be set for 100, but the glass has been holding at 93 for about an hour.