Do you have your heat pad in the tank? Is it a reptile under tank heater or just a human heating pad?
I've been frustrated with the amount of heat being lost under the tank by the heater. So i've spent the last month trying to figure out how to put it in the tank without the risk of my geckos getting to close to the elements. I found that a frame with the appropriate type of glass, raised and then vented works to make the heater portable so it can be moved from tank to tank. I'm going to start testing the temps later this week. I'm covering the frame in ceramic tiles too. I just want to see if the ambient temps can be raised this way and a portable unit saves on cost when upgrading to new tanks. It sucks that the warmth is only where the elements are and the 10-20 rated UTH's are only 6X8 inches so thats not alot of area to keep warm especially with the humid hide over it. Its just an idea i have so i don't know if it will work out.
Red 
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Crested Gecko Zeek:1.0
LEOS: Boo: 1.0 normal , Bronx & Nala: 1.1 blizzard,
Lily: 0.1 patternless, Abby: 0.1 albino, Zoe: 0.1 reduced pattern, Dot: 0.1 hypo
Chip: 1.0 papillion (small dog)