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Floor 10 of 17

Luigi's Mansion 3: B2 Boilerworks walkthrough

The flooded machine level under the hotel: sewer puzzles on a duck float and a fight in a water tank.

  • About 19–32 min in the videos
  • 2 parts · 5 steps
  • 1 boss

Compiled from 2 playthrough videos and 7 guides · checked Oct 18, 2026

0 of 2 done
Video: ProsafiaGaming on YouTube. Loads from youtube-nocookie.com only when you press play.

What each player can do here

P1 · Luigi
  • Luigi holds the Poltergust G-00 and the flashlight: stun ghosts with the Strobulb, then vacuum and slam them. The run only ends if Luigi runs out of health.
  • Luigi drives the duck float through the water with the vacuum.
P2 · Gooigi
  • Gooigi walks over spikes and slips through bars and tight spaces that stop Luigi. Water and fire empty his health at once and send him back to Luigi.
  • Water melts Gooigi, so on this floor he takes the dry routes: pipes, valves and chains above the water.

If your skill levels differ: IGN notes this floor needs Luigi and Gooigi about equally, so both players stay busy. How to split the roles

The sewers

Part 1 of 2. Work through the sewer puzzles to reach the tank.

  1. BothSummon Gooigi on dry land before Luigi gets on the duck float.
  2. BothGooigi travels through the pipes while Luigi, on the float, turns the valves that shut off the water in his way; at the end Gooigi pulls the chain that lifts the gate for Luigi.

Where people tend to fall

  • The float pops in one hit, and that is an instant loss of the attempt; steer clear of spikes and mines.

The tank

Part 2 of 2. Beat the mechanic ghost and fish the button out of the tank.

  1. LuigiHe fans himself around the tank and drops mines. Pop his rubber ring by pushing him into the spiked walls or into an exploding mine.
  2. BothWhen he lands on the edge, flash and vacuum him; the wiki suggests letting Gooigi do the vacuuming while Luigi stays in the tank.
  3. LuigiThe button sinks to the bottom: drain the tank with the lever at the back and climb down for it.

Boss

ClemThe mechanic ghost

  1. In the water: Pop his rubber ring on the spikes or a mine.
  2. On dry land: Flash him while he puts on a new ring, then vacuum and slam.

Achievements and extras

  • Six gems are hidden on this floor, and a Boo turns up here once you have the floor's elevator button and come back later.
  • Not every gem here can be reached on the first visit; you come back to this floor later.
Sources (9)

Steps compiled from 2 playthrough videos and 7 text guides, checked Oct 18, 2026, and written in our own words. We did not play the game for this guide.