I very much appreciate the input on the heater -actually it works
with a delay so I will leave it for some time the way it is.

The reason I asked is because I have had some smell
getting out of the vent besides the non-stop heat
and the inability to quickly change the temp.
It smelled like break fluid or Armorall, so either the person
who had the car sprayed some armorall into the plastic
compartment where the vents intake air from the
windshield or there could be some brake/ ABS fluid
leaking in the vicinity-do the 300E have a visible washer underneath the brake pump close to the round drum base or is the washer hidden?. Here it is not visible-maybe its not present. It apears as the brake pump has been replaced along with the dark round "drum" and some of the fluid seaped there and dryed onto the black drums surface.
Michael