On Friday my Carrier Thermostat went blank... and the heat is no longer working. I am assuming this happened because the furnace is no longer given any direction on what to be doing. The thermostat does not take batteries, so that is not the problem. The fan was still running for the furnace. We refreshed the circuit breaker... that did nothing. I ignorantly have not changed my filter in quiet some time. Could this be the problem? I am wondering if air was not getting though the filter and as a safety precaution the unit shut down? That is why the fan keeps going? I was going to question around….and then go and buy a new Carrier thermostat and see if that fixes the problem? Any thoughts??