Heating Issues

[Bogertophis]

Dig down to the uth and feel the glass with your hand. I bet you find it BLAZING hot. No more than a 1/4 inch of substrate should be over it.

To the OP: I pretty much agree ^ ^ ^. It depends on the type & density of the substrate, but for sure, you don't want deep substrate over the UTH, because it becomes "insulation" that prevents the heat from rising INTO the enclosure where it's needed, & instead, it can overheat the UTH to an unsafe level.

I use UTH on all my snake's homes, & have for decades- it's most effective if you limit the amount of substrate over the UTH, but I also place the snake's "warm" hide over the UTH, so it becomes like a warm "cave" for the snake. UTH is usually low wattage & the belly-heat is appreciated (IMO) by our snakes, but depending on your ambient room/home temperatures, you might need additional heat sources to maintain the proper temperatures in the enclosure- depending on what species you're keeping.

And all heat sources must be regulated for safety & temperatures checked regularly to make sure they aren't excessive (which can cause neurological damage or even burns & death to your pet!) so please use thermostats (or in some cases, at least a rheostat -aka lamp dimmer) for safety.