Heater blows cold air?

I changed the blower motor and the thermostat the coolant levels are good. I've checked the blend doors are opening and shutting like they should but the heater only blows cold air. I changed the water pump around the middle of last summer and it has around 20,000 miles on it. When it is at normal running temperature, which I believe we I am 190, both heater core hoses are cold, they do not even get warm at all, and the truck does not overheat at all.