for what its worth I have a set of drains under my bed. They are both buried in a tangle of wires. Both are hard to spot but one is very hard under a bunch of wires.
The two in my kitchen are buried behind a drawer that must be removed to get to them.
You should be able to spot all the drains if you check under the rig....blue for cold and red for hot...just open stubs of tubing point down out of the floor.