Heater valve with A/C

[qkcuda]

I am having a strange problem. I have been struggling with an overheating issue. The car has factory A/C and the heater is in the on position. I drive for a while and the temperature stays steady at around 180. Suddenly I noticed the temperature creeping up. At the same time I notice no heat. I get back and put the heat gun on it and the water pump shows 205. One heater hose shows 185 and the other one is at 140. I had run it in the garage earlier and both heater hoses were within 10 degrees of each other. I cannot figure out how the heater just stops circulating coolant when I don't change anything. Any ideas?