Heater blows cold air?

I would check the engine coolant level first and then feel each of the heater hoses when the engine is warm. Here is a video that can help us see what is going on, also does the heat working on either side or just not on one side? If it is just the right side, then I would say it will be the right-side blend door actuator.

https://www.youtube.com/watch?v=SNRb6pSwYuU&t

Can I ask if the airflow to the correct vents is working? Please go over the video and get back to me.

Thanks for the reply. The coolant level is good and has been good since I did the work. Did not get a chance to check heater core hoses for possible core failure or air pocket, but before I get it back to dig in more (friend's car). Is there anything else you can suggest to keep an eye for? I'll reply back after the car is in my possession.
Thanks a lot

And yes, air flow is going to the right vents and is blowing out of all of them equally.

and heat is blowing cold air from all vents.

Oh yes, the heater core can have air in it, I would remove the radiator cap, start the engine so it can get warm, then jack the front of the car up, and then the rear of the car to help get the air bubbles out. You should see the coolant level drop a little if this is the problem.

https://www.2carpros.com/articles/jack-up-and-lift-your-car-safely

Let me know.

Good morning. I'll let you know once get a chance to do it. Thank you very much.

You are welcome, I hope it helps :)

Hi, Ken. I wanted to update you.
! heater core hose was slightly warm and the other one pretty much cold. Tried airing it out, ifted front, then back and nothing. Disconnected the hoses, blew air out and ran new coolant through it and it worked like a charm. )
Thank you very much and I'll let you know if have any other questions or concerns.

Glad you could get it fixed, thanks for letting us know. Please use 2CarPros anytime we are here to help.

Appreciate you.