where is this valve located and is it fairly easy to replace ?
heater control valve on 1994 Buick Roadmaster
The heater control valve on your 1994 Buick Roadmaster should be located in one of the heater hoses under the hood and should be fairly easy to replace. Have a look under your hood and see if you can find the valve (inlet and outlet with a vacuum hose connected in the middle). If you can find the valve then you should be able to tell if you can replace it your self.