I have no heat anywhere - not on the floor or the defrosters or the vents. The blower works fine and you can switch to the different positions (defrost, floor, etc.) The hoses going into and out of the heater core are both HOT. The vehicle is equipped with the C86 climate control system. Regardless of where the temp is set, it stays the same ~ COOL. The temperature outside this morning was -7 F, but it still defrosted my windshield, so the temp is just a little bit warmer than the outside. :confused:

Just because both heater hoses are hot doesn't mean that the heater core isn't 90% blocked.

Try a prestone flush kit, and reverse the heaters hoses while doing this. With a little bit of luck it'll flush any garbage out..

Lots of luck, and I hope that it's warmer there than it has been here the last month

Edit:

Welcome to Automotive Forum!

i have had the almost same probelm. i did the reverse heater core flush. i didn't use anything but water. out came little jelly balls. added more anti freeze and new radiator cap. now i have to turn the fan to low speed and sometimes the temp down as it's too hot...99 blazer lt

Need to check and see if blend air door motor is working.

I agree wtih OBP. Probably a blocked heater core. Try the reverse flush. Usually has really good results.