Sometimes the blower is set to run constantly in manual mode. The problem is that after switching from manual mode to auto mode, blower on the gas furnace continues to run constantly. It will go back to cycling normally in auto mode after shutting the heating/ac unit down and restarting in auto mode. Any ideas on what could be causing this?
The thermostat (Honeywell Chronotherm III T8600C) has also been making clicking sounds that last about a minute or so, at irregular intervals several times per week. Everytime this happens, display shows "-AC" on every click. But the clicking has been going on about a year, much longer than the constantly running blower problem.