Heat tape/mat is not heating up?

[.leopardgeckos.]

I purchased a 8" x 8" Exo Terra Heat Wave today, along with a Zoo Med 500R Thermostat for my 29 gallon tank. So far the warm side is only 78° Fahrenheit and the cool side is 72° Fahrenheit, which is too cool obviously. Before I had any heat pad, it was around 65-71° Fahrenheit. So the temperatures didn't go up very high as you can tell. It took about an hour and a half for these temperatures to even get this high. I guess I am just not being patient. How long do you think it will take the heat pad to warm up some more? It is only 8 watts, and I thought it was the 25 watt.. I would of returned the 8 watt, but I already stuck it on the tank. :main_no: Oh well.. so anyways, back to my original question, how long do you think it will take the heat pad to warm up?

And one more thing - it's in the garage, mainly because of my parents.

 

[ElapidSVT]

it should take several hours for it to reach equalibrium. garage doesn't sound like a very good place for an animal that needs 90F belly heat to be.
i'd recommend getting something that can provied more heat or move the animal inside so the heating element you have can get the environment to the proper temperature.

good luck!