Dodge Repair: heater not working right, heater hoses, dodge stratus

Question
Hello Steve,

I have a 2002 Dodge Stratus 2.7L with a heater problem.
The heater will only blow hot air if I have the engine running at least 2000rpms .
If I am just sitting at an idle, then it starts blowing cold air.
I'm thinking it's a problem with the air flow door, but I'm not sure what's causing it or what I can do to fix it.
I'd rather not tear the dash apart if I don't have to.
How can I fix this?
Thanks a lot,
Tom VanRoekel

Answer
Tom,

First thing to do is make sure the radiator is full of coolant,  If so, You want to remove both heater hoses and try and flush the core out. Place a garden hose on one side of the heater core and shoot the water through it. Then change the direction and do it from the other side . Do this a few times untill you get a clean flow through the core.

The problem is a flow problem not a door problem, the doors if bad would not work at any rpms.

Good luck,
steve