Heater blowing cold air.

Most likely it is the heater control valve that shifts air from blowing across your heater core to your air conditioner core.

If your fan works and your car is fairly new..meaning your heater core isn't dirty and full of craap...then it is the climate cotrol valve.
If you are lucky, it might be a thermostat that is bad and blocking hot water from entering your heater core. Bottom line, if hot water doesn't circulate thru that little heater core, you won't get heat.
You might be able to look under the hood and grab the hot water lines that go thru the firewall and feed your heater core. If they feel cold to the touch after engine has warmed up, then you aren't getting circulating water to the heater core. If they feel nice and warm, then the heater core is fine, but your climate control valve has closed off the fan that blows across the core to disperse heat into the cabin

What have you checked so far ?
Radiator full of coolant ? Heater hoses getting hot ?

I like that you were knowledgeable to check both coolant lines tells me you are getting hot coolant through the heater core next thing to check will be the blend door on the inside of your vehicle. The blend door is a door that switches from cold air duct to heater duct depending on what you are using at the time. If it is stuck on the cold air duct you will not get any heat sometimes these doors are vacuum actuated and sometimes they are electrically actuated most the time you are able to see the movement of the motor from inside if you don't see any movement but you hear it move chances are it is the door blend I hope this helps.

To troubleshoot this types of problem,click the link below :---

All types of car overheating problems and troubleshooting? http://technoanswers.blogspot.com/2011/11/all-types-of-car-overheating-problems.html

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heater blows through defrost?

-http://howtobyme.blogspot.in/2012/02/heater-blows-only-from-defrost.html
--------Go through the procedure to confirm the issue.

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Engine Overheats and heater blowing cold?

http://howtobyme.blogspot.com/2011/11/engine-overheats-and-heater-blowing.html

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Heat blows cold on drivers side and hot on passenger side?

http://schematicsdiagram.blogspot.com/2011/12/heat-blows-cold-on-drivers-side-and-hot.html

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This will help.Thanks.

Flapper door inside duct work most likely stuck open not allowing heat to come thru the heater core.

The fan that blows the air through the ducts is probably bad.

You need to check the heater core it has two hoses going to it feel of them if one is hot and the other cold heater core is stopped up replace it or flush it out if they are both hot it can be the switch or a vacuum line the vacuum line will be on the passenger side under the hood where the airconditioner hoses go in the body

A thermostat stuck in the open position can cause both of these problems

It seems to me if your heater core is hot, and the fan blows cold air, then your ducting is closed off. Try and see if your duct door is opening up. You say you changed out your controls, but it sounds as though it wasn't your controls that were bad, but what they control is not opening up.
It's all well and good that the heater core is getting hot, but if the fan cannot deliver that hot air passing through it, then walah.
It has to be an air duct obstruction. Either the ducting is collapsed, the duct door is not opening, or you have some obstruction blocking the ducting. My guess, because that is all I can give you without seeing for myself, is that the linkeage or solonoid that opens the duct door is not working. Older cars had a cable, but I believe newer use a solonoid to operate the opening and closing of the door. The door is there so you don't get the heat from the core when you are using AC.
Hope this helps.