"Untertisch" is obviously the opposite of 'tabletop' - I just can't think of a better term than 'freestanding'

is how I always translate this - I've had no complaints so far....
The "Tisch" is a Waschtisch, I assume?

--------------------------------------------------
Note added at 2004-01-20 17:04:49 (GMT)
--------------------------------------------------

Even the local builders here would find it silly to put the heater anywhere other than under the washbasin, wouldn\'t they....

German term (edited): Untertischhei�wasserbereiter

This is the U.S. term; they are quite unusual here
What it means is that the application in question requires higher pressure than these or "drucklose" provide

.. if we're talking sinks

www.tlc-direct.co.uk/Main_Index/Water_Heating_Index/ Storage_Water_Heaters (for example)

"build(-)under" is another commonly used adjective for kitchen/bathroom units.