Themostat Help

[alf1096]

I was flushing out the radiator by draining the pet-cock and I took off the top radiator hose. The question I have is that if I run water in the therm housing it goes right through the engine. If I fill up the radiator with a hose it will come out the therm housing. If the stat was close shouldnt it block the water off at least one way? could the stat be froze open. I live in texas and it seems to take the truck a while to warm up and on the highway it runs 160 but in town like 190 should there be that much difference. I just bought the truck no idea what temp stat is in it.