Heater Problems

[///Sniper535]

It seems to me that my climate control is acting up. I no longer get warm air, only cold, and hot, and the passenger side only blows cold unless max heat is used. On the temp. dial, it blows cold, but as soon as you move the dial to where the red starts, it gets hot. Also, the thubwheel temp controls on the vents don't affect the temp any more.

What could have failed? Heater Valve? I also started to hear some kind of rattle noise when I start driving my car, it's not all the time but it comes from behind the dash on the driver side.

[Blitzkrieg Bob]

I'd suspect the heater valves first