I have a BesTech BT110D Digital Non-Programmable Thermostat that is 3 months old. Just started noticing that the set temp for the heat seems to not be working. I set the set temp for heat at 70 degrees and unit does not shut off. I have watched the set temp light go off when it hits my set temp and the thermostat makes a clicking noise but the heat keeps climbing until 80 then I end up having to turn from heat position to off position then it shuts off after 20 seconds or so. Anybody have any ideas as to why it is doing that. Maybe just a cheap thermostat went bad already. It does have a year warranty so.