My heat will not blow out of my dash board but it blows A/c at all times the rear heat works just fine I notice today that the A/c pump was on and the lines where hot and the a/c lines where Ice cold

I check the actuator door it seems to be working the motor swings it back and forth but I noticed there is a button on the dashboard that sucks air from outside or the other setting would be to recirculate the air in the vehicle when I push that button I noticed the temperature of the air changes From lukewarm to ice cold

The coolant level is full I pulled the hoses off flush the coolant made sure I got all the air out of it still no heat in the front of the vehicle now the rear he is working for some reason I cannot get the front dash panel to blow warm air

Ok I finally found the problem it was the heater core plugged up I just didn’t take the tees off that feed the rear heater the first time I flushed the system out

Thanks for all the help

06 tahoe rear heater workin blower motor works fine only cool air actuator good also but when I bought the tahoe the front core didn't work and the owner replaced it before i took it off the lot.. I have 2 aluminum hoses that isn't hooked to any thing that I believe should of went to the condenser for my a/c but somehow another it is just like the one on my 2000 Silverado 4x4 and I thought it should have all the hoses there intact ?? Anyway I never dealt with the rear hvac before but I'm in need of help I'm 100% disabled and have 4 kids I'm tryna raise and it's getting cold in ky. lol I'd appreciate any advice at this point but thanks in advance..J.C.G