The Boiler is the machine that heats water into steam. Steam is one of Sandustry's core fluids, used across thermal processing and the energy production chain.
Note: the official wiki does not yet have a dedicated Boiler page. This guide is compiled from the community boiling guide and in-game thermal mechanics, so treat specifics as needs-testing.
How it works
The Boiler is a hot thermal machine. Thermal machines refine materials by temperature:
- Hot machines move a material from solid → liquid → gas.
- Cold machines reverse it, gas → liquid → solid.
The Boiler takes water (liquid) and outputs steam (gas). It is one of the most direct examples of the thermal system in action. Steam follows simple physics: it rises until it hits a ceiling, where it pools (just like water pools on the floor); with no ceiling above, it keeps rising until it reaches the sky, condenses, and falls back as rain. Use blocks and chimneys to route the rising steam where you want it.
The four parts of a boiler setup
Community boiling guides break a working boiler into four pieces:
- Water input — feed water in through pipes and pumps from underground sources or storage.
- Heating — a heat source converts the incoming water into rising steam.
- Steam control — steam rises high and forms clouds, so extended chimneys, blocks or filters guide the flow instead of letting it escape.
- Contaminant prevention — filters stop unwanted materials (like snow or lava) from entering the water supply and breaking the conversion.
Steam's role in the energy chain
Steam is a middle step in the late-game Energy production chain:
Amethelis → Steam → Dry Amethelis → (heat) → Florin (gas) → (cool) → Florinol (liquid) → Battery
In that chain, Amethelis is refined into steam, then dried further. Steam itself is not the final product — it is a stepping stone toward Florin and Florinol, which end up in a Battery.
Sourcing water
Water is the Boiler's input, so you need a supply. Two options:
- Catch a Lumling with a Corraller — it produces water.
- Pump it from a water source using a Pump + Pipe + Liquid Vent.
- Boil it with a Flamethrower — before you unlock Pipes, heating water or snow with a Flamethrower (or the Rocket Launcher's napalm upgrade) turns it into steam that rises, condenses, and rains back down as water. This is the game's early way to move water to the surface.
For the full thermal picture, see the tips and tricks guide and the lava page for how heat and cold interact with terrain.
For another machine in the production chain, continue to the Kinetic Slag Press.