Heating pad problems

[WhompingWillow]

That just sounds like a fluctuation due to the "on/off" thermostat, as opposed to proportional thermostats.

^^ This 100% OP. Jumpstart is an on/off thermostat with a +/- 2 degree difference in temperature control. So if you set the thermostat to 88, it will cool down to 86 before turning the UTH on and will heat up to 90 before turning off. UTH and on/off thermostat temps are really approximate at best. There will be a difference between what you set the thermostat for and glass temperature due to things like ambient room temp, trapped heat, the fact that it's a pain in the butt to get a UTH to lay completely flat over a probe, etc. The 2 important things are that you aim for anywhere between 88-90 as a hot spot and that the thermostat will prevent the UTH from getting too hot, therefore preventing burns.

Your best bet may be to supplement your hot side with a heat lamp on a dimmer or CHE on a separate thermostat to prevent the temp swings. I use infrared bulbs with dimmers and UTH with my glass setups. All of my UTHs are on Jumpstarts. Both heating methods combined with my ambient room temperature means none of my thermostats need to be set higher than 88 degrees. Most are set between 86-88 to achieve a 90 degree hot spot. You just have to experiment to see what works best in your environment. Hope this helps!

Edited to say that if you have a smaller enclosure (ie, 10 gallon), only supplement with a heat lamp/CHE if you also need to bring up your ambient temps.