2003 Mercedes Benz E Class interior heating

Check your heater linkage to hot/cold air distribution is secure,if it,s cables then it may have simply come out the clip but if it,s an electronic heater unit with motor control then you may have no choice but to put it into a garage.

Could be a faulty heater control valve , stuck in cold position .

This should help ,

http://www.justanswer.com/mercedes/1j7hy-2003-e240-heater-will-not-output-heat-blower-works.html

Thanks for the feedback and ideas. As a complete novice in this area and little experience in car maintenance, is there anything easy that I can do? If this problem is linked to the heater control valve, is there a chance that it will free itself up and start working again? Not sure what I can do to get this working, would really appreciate any help in this area.

All you can do is check the basic,s I.e water Tempreature going to and from heater unit,check the hoses are both hot ,linkages to heater are all on and electrical connection,s .It,s really a job for a garage to diagnose due to the complex design of the system,

If you rap the heater valve it may clear and move .Otherwise you may be able to move it manually by hand .