Heat Mat + Thermostat Set Up Not Working?

[Dev_DeCoste]

Hey everyone..

So I picked up a Zilla Thermostat today to control my heat mat (which is Zoo Med). When I ran the mat without a thermostat the thermometer read about 82 degrees throughout the whole tank. I set up the thermostat about 4 or 5 hours ago, set it to 90 degrees and since the thermometer has dropped down to about 65-70. I just cranked the thermostat up to about 100 to see if maybe there's a heat loss going through the substrate (Only have newspaper and maybe 1" of Aspen bedding). I also have 2/3 of the top tin foiled now for humidity... That's at least working out haha. Any ideas of what could be going on? Did I buy a dud or something? I was all excited to have my guys set up finally 100% complete and now he's all chilly and junk ha

http://www.amazon.com/Zilla-11939-Te...med+thermostat

http://www.amazon.com/Repti-Therm-Un...eat+mat+medium

Thanks!
Dev