My mercedes is a 1989 300TE Wagon gas engine and have checked the wire connections to the heater valve but valve does not seem to open as can't get heat in to car.

Looked up part at ********,AZ and shows a Bosch part # 1147412037. Can someone please walk me thru R&R this valve. Saw the 2 hoses connecting to the valve and looks like the 2 rubber fasteners slide out of grooves to remove valve after disconnecting the 2 water hoses. Is this correct and does the water system have to be burped so as not to get a vapor type lock?

This is my first post and am new to list so thanks for any help offered.

Regards,
Ron