Purchased my 2013 Volt new. It has mostly been trouble free. Lately, I have been having intermittent heating issues, no heat and cold air from the vents. Heater on HI and on comfort mode. Auto defog off. The cold icon is on, no heat icon. Outside temp is 40F. When I turn on defrost, there is no vent change. A few years ago, someone on this forum suggested pulling the F5 fuse (HVAC) on the driver's side instrument panel to reset the HVAC. It worked when I tried it back then. It worked again, however, it is happening more frequently and every time I pull the F5 fuse, things go back to normal. The car is out of warranty. When the heat icon is on, I get heat. Any ideas aside from pulling the fuse.