Thermostat - what am I doing wrong?

[Reptilian Feline]

I have a thermostat, a habistat dimming one, with night eye, and two 75W CHEs plugged into it. It has a light that tells if it's heating, a light that tells that it's in night mode, and a light to show that it's on. So far it's almost always heating, and even if I've put the dial to 84F and the probe is close to one of the CHE's. Tank Girl seems to think it's a bit on the hot side, so I took my thermometer probe and placed it where the thermostat probe is, and it shows a bit closer to 90F. I'm confused! Is my thermostat broken? Is there something I'm missing in the setup? I can turn it down further, but then it will still not match the heat and temperature and be on constantly, and I won't be able to trust it if the outside temp goes up.

 

[Sterant]

Can you post a picture of the setup that includes the thermostat, the connections to it, the CHE's and the probe?

 

[teresaf]

I didn't even use a thermostat. I had several thermometer / hygrometers probes hanging in different areas in my enclosure. I have attached a pic of the one I used. I put one in coldest corner and basking spot of enclosure and adjusted CHEs and lamps accordingly. I left them in permanently and verified the temp every time I passed the enclosure.

Of course my enclosure wasn't near any heat sources or air condition vents or near window that would adjust the temperatures externally