So, today I got my Thermostats and to be honest I don't know what I am doing. >.>

So, I got my Thermostat maybe about an hour ago and do NOT know what I am doing....
Obviously, you have to plug the Heat Mat in the thermostat outlet and set it, right? I mean obviously you have to plug the thermostat to the wall outlet, of course, but the UTH not getting hot, I just plugged it up to the heat mat about maybe 20 minutes ago, I just check it, just now, to check if I can feel it through the glass, well I can't.

Do I have to give it more time to heat up or should it have heat up already?

My mom had to leave about 20 minutes ago but she did help me lift the tank to get the probe between the UTH and the tank, so, help would be appreciated!

Thank you.