Could anyone tell me what position corresponds to what for the heater control valve? The arm on my HCV is completely out and if I push it in it pops back out and no matter what I do, it stays out. Does this mean the coolant is passing through the heater core or not?

This problem of having no/low heat is driving me nuts...

Thanks

 

The arm is always full out - when you want less or no heat, I think it pulls the arm back. If you're having trouble with heat, check your thermostat or, more likely, air in your heater core.