Review on 🌡️ DZS Elec Temperature Controller: -50 to 110 Celsius / (-58 to 230 F) Programmable Thermostat Module for Heating/Cooling Control, DC 12V, NTC Waterproof Sensor Probe, LED Display by Joseph Adaymiln

First, if you have other sensors in the liquid at the same time, it can be caused. Second, and more importantly, the reading fluctuates so much that it keeps turning on and off no matter how you set it. Changing the return differential to try turning it on less will not help because as soon as you increase the return differential it will wobble more. Example: Let's say you need 68 degrees of cooling, but you don't want this thing to turn on and off many times per second, so do the inverse difference of 1, 2, maybe 3 degrees, so let's say 3 degrees. she will cool down. to 68, then off and on to 71. Sounds right, it doesn't turn on and off every million. NOT RIGHT! Once you get to 3 degrees the reading starts to fluctuate about 3 degrees so it shows 68 and after a second it shows 71 and jumps between those two values with many different readings constantly changing. fast SO IT WILL TURN ON/OFF MANY MORE TIMES PER MINUTE. THIS WILL CARRY THE RELAY AND I DON'T EXPECT IT TO TAKE LONG!