The air condition on e500 works but when i turn the heat on it blows cold air. W on 2005 Mercedes-Benz E500

Where is the heating element on this car and is it something I can buy and fix without taking it ot the dealer.

Asked by for the 2005 Mercedes-Benz E500
Under the hood next to the bulkhead on the left looking from the front of the car, you will find hot water pipes going into the heater unit. There is a valve with two wires going into it ( solenoid valve), it's stuck in the off position. Check for power, tap it , or change it. I had exactly the same prob. The valve is situated on one of the pipes, and is not easy to change. Hope this helps...