Mechanical room
Put the sensor where water will hit the floor, not where the brochure shows a clean photo.
Heaters, PRVs, tanks, and floor drains are the usual start. A sensor on a high shelf watches dust.
Floor level, near the equipment that holds water.
Tanks, heaters, and pumps first.
Keep it out of the regular wash-down path if staff hose the floor.
False alarms train people to ignore the next one.
Tie it to a person who can isolate the room.
A 3 a.m. beep to a general inbox is not a plan.
Questions people ask
Will one sensor cover the whole mechanical room?
Only if the floor really drains to that point. Large rooms need more than one.
Does a sensor replace visits?
No. It shortens the time to notice. It does not inspect the piping.