Unfortunately there are a few items that are at risk. The corrosion is from the anti-freeze not being changed at regular service intervals. Some manufacturers use anti-freeze types that break down and turn into a think goo clogging the cooling system.
The heater in your car is part of the cooling system and works from fluid passing through a Heater Core. It is a little radiator that is mounted under the dash. When you turn the temperature up your are allowing coolant to flow into it and since the coolant has so many contaminants, it is likely the heater core is so corroded it is not able to allow fluid through or transfer heat to the heating system.
There is the possibility that the valve has failed, but with the condition of the fluid it is almost certainly in need of replacement. Eventually it will start leaking into the passenger compartment. Also, the car may overheat and the gauges and lights to warn that the car is overhesting might not work as they could be corroded over.
You can by-pass the heater core by following the intake and exit hoses out of the firewal from the core to the block, romove one of the hases and remove the other hose at one end and turn it back to seal the other heater core inlet/outlet up and do the same at the engine. This is not optimal and you will not have heat, but then you will only have to repair the cooling system as pertaining to the engine. The heater core costs a lot to replace as the part is as much as a radiator and the labor is generally 8 or more hours.
Let me know how I can help in your decision making process. Sorry that you have the problem, but at least you caught it before somethng failed and damaged the motor or leaked in the interior.
Tuesday, November 23rd, 2010 AT 12:32 AM