luke warm heat
#1
#2
#4
#5
You could have an air pocket but to flush the heater core there is two hoses running into the firewall them and run your garden hose through the colder hose for about 5 minutes or so when I did it I let it heat up enough to where I could feel one of the hoses get warm and than I pulled the colder one and run the water in that way let me know if that helps at all
#6
#9
#10