Just bought an E270 Avantgarde (2002). Very happy BUT today tried to get hot air and no joy. Looking at previous threads it appeears to be a common problem on the W211 anda advice is to give it a firm tap on the auto valve (?) which is a bit of a pig to get to on the RHD models like mone. My question is what does this look like? May be abvious to you old hands but this is my first Merc so want to be sure i am tappingthe right bit! This does seem likely as a culprit as I bought it from a small independent dealer and it has probably been sitting around for a while. Any tips greatly appreciated.