The SureSTAT TS110 thermostat has the features I need to control fans for the geothermal earth battery system in my greenhouse. One thermostat kicks the fans on when the temperature gets above 70 degrees Fahrenheit during the day, so they can push warm air underground to heat the earth up. The other thermostat kicks the fans on at night when the temperature gets below 45 degrees, to bring that warmth back up. The cold thermostat wasn't calibrated right, and had some damage out of the box. I asked ACF Greenhouse support what I could do to fix it. They determined it was a faulty thermostat and offered to send me a new one. This solution was much better than what I was expecting. I got the replacement two days later through priority shipping. I am very impressed with their customer service and am a happy customer. I have a third thermostat shown in the photo controlling the exhaust fan and louvres.