2000 Kia Sportage no heat

Vehicle was overheating and only blowing cold air through the vents. I replaced the cylinder head, thermostat and radiator. The vehicle no longer over heats, but it still only blows cold air out of the vents. I was able to test the temp at the heater hoses. The temp going into the heater core is 147 degrees and coming out is 128 degrees.I removed the dash to see if the heater box itself is the issue, but all the controls and blend door are working normal. I am pulling my hair out as what could be causing this problem of only cold air. Could you please help me.
thank you
troy