One key element of staying at a hotel is that you can get a bath. Dom 003 fails at this - even though our room had a shower, the hot water was a mere trickle. So taking a shower required lots of patience, and controlling the temperature was impossible - it varied between cold and very hot.
The hotel itself seems to be in a poor state. The tapestry was beginning to peel off, three light bulbs in the room did not work, and a chair was missing so the desk could not be used.
And the elevator (lift) was out of order all the time, even though the staff did not care to put a sign saying “out of order”.
It’s a shame because the location is good, just around the corner from the Kölner Dom.