Quote Originally Posted by ChrisBowsman View Post
The t-stat will be set to provide enough juice to heat the UTH to 92 degrees. If the r-stat is set to allow the passage of enough to heat it to 95, there is no problem.

First, if the thermostat is set to heat to 92 degrees, you will never see 95 degrees regardless of whether there is a rheostat inline or not. The thermostat is going to turn on and off based on the probe temperature. The risk is now the fact that by introducing another ~12 feet of wire (the length of the run to and from the inline rheostat), and it's associated resistance, the power draw against the thermostat is going to be greater than it needs to be, and which can shorten it's lifetime considerably.

In either case, the answer is simply to make sure the thermostat will shut down in the case of a problem, and to have a rheostat on-hand to replace it with temporarily if needed. Anything else will shorten the lifespan of the equipment, and potentially put the animals in unnecessary risk.