Something I have learned is a 15.00 temp gun is well worth the money. I have learned that trusting the temps on a thermostat is not the best way to go. I have my hot side set at around 95 degrees to keep the hot side at 89 and the cool side is is on 81 and keeps the cool side at 80. Exact same thermostat and same probe placement. Just because you think it is at 30 degrees does not mean that it is.