Mercedes is a good company and the answer to you're queston is NO.
Disconnect the send and return lines from the heater core and use a hose coupling and hose clamps to connect these two lines together
it is probably the heater control valve see my tutorial on this at http://www.benzworld.org/forums/w201-190e-d-class/1358590-troubleshooting-mercedes-benz-190-e-d-210-tempmatic-climate-control-system.html#post2716281
How do you remove a radio from a 190E?
There are two possibilities. Its either on the overhead console by the rear view mirror or on the center dash control switches below the heater vents.
It sounds like you have no coolant flow through the heater core or the core is plugged
A Mercedes 190e doesn't have a carburetor. They are fuel injected.
If you look on the backside of the climate control unit in the dash you will find a glass buss style fuse. It will be blown. Replace the fuse and your fan will stay on with your headlights.
Sounds like low coolant or air in the cooling system
Why does my fuel pump keep running on my 1984 190E
oil filter on a Mercedes 190E 1986 is in the back of engine
For a 190E 1984 Model, it is about 60Litres, this is 13 Gallons(UK) or 16 Gallons(US). For a 190E 1993 Model it should be the same +/- 5Litres.
I heard that you can take the temperature control wheel out and reheat the solder points around the dial. I have the same problem on an '87 190e. I'm still trying to figure out how to take the console out to get to the temp wheel. You have a vacuum leak. Or possibly a bad heater valve. Open the hood, remove the leaf tray, and locate it on on the passenger side. It has a red vacuum hose sticking in the top of it. Check it for water leaks, and check it for vacuum leaks using a Mityvac or some other vacuum tester. When vacuum is applied, the valve is closed, blocking hot water to the core. If the valve checks out, put the tester on the red vacuum line and see if vacuum is present in the pipe. If not, then you have a problem elsewhere and the valve is fine. Possibly a vacuum leak as indicated above. JC.