Quote Originally Posted by Daigga View Post
So today I finally got around to wiring part of my larger rack and hooked it up to a simple hydrofarm thermostat. The issue I'm hitting right away is that it seems to run either all or nothing in terms of power, and the probe takes a long time to adjust to the temp changes (probe is attached to THG tape with electrical tape). I have it set to 95 right now since it seemed liked that was about where it was actually giving me 90, which is what I wanted. The temps, on the other hand, fluctuate up to between 115 and 120 while it's heating and down to 87 when it isn't according to my infrared thermometer. These cycles take about 3 minutes or so, and I'm very uncomfortable with these temperature fluctuations. Only 3 shelves are wired up right now so I don't have any snakes on it.

Is it going to keep doing this, or will it eventually balance itself out? Should I just junk this thing and keep up with the ambient room temp until I can get a herpstat?
Well they are on/off thermostats so it's only ever going to be on or off. I don't believe there's a way to set their buffer time between kicking on. An STC 1000 would allow you to change that but is still an on/off controller. (I use a pair of them for my UTH and heat lamp)

Where's the probe located relative to a hot spot? Do you have a second way to check the temps because that's a very huge difference in temperature? Maybe your IR thermometer is being finicky.