I have a 1999 toyota avalon and the heater doesn't work. The hoses are hot on both sides of the heater control valve, but it just blows cold air. The cable that connects to the heater control valve is frozen. I removed it from the valve, but still no heat. Any suggestions?

replace the heater control valve then, if opening it up manually does not get heat

Sounds like a dash control problem, see if you can find a used dash controller in a salvage yard or on Ebay.