Heat Source
The thing actually providing Heat.
Heat Production in Sandustry
A working Heat setup needs an active Heat source, a continuous Heat path, and a consumer that is actually touching or receiving that Heat path. Having Lava or a hot Thermal Buffer nearby is not enough if the connection between stages is broken.
Heat production
Source · Lava
↓
Path
Thermal Buffer
↓
Consumer · Smelter
Check
Source → Path → Consumer
Most common problem: a broken Heat connection.
Jump to section
How Heat works
If one stage breaks, the entire Heat chain stops.
Source
Lava
↓
Path
Thermal Buffer
↓
Consumer
Smelter
Heat Path
The structures or physical setup that allow Heat to reach the next part of the factory.
Consumer
A machine or process that only works while Heat is available.
Heat Source vs Heat Path vs Consumer
A hot Buffer does not mean the consumer is heated. The final consumer must be part of a valid Heat path too.
Source✓
Thermal Buffer✓
Consumer✕
does not mean the Heat system is working.
Buffer active ≠ consumer heated
A hot Buffer does not mean the consumer is heated. The final consumer must be part of a valid Heat path too.
How to use Lava for Heat
Lava is useful as a Heat source, but good Heat factories control where the Lava sits and where the Heat leaves it instead of letting Lava flow freely through the production area.
Bad
Lava
~~~~~~~~
~~~~~~~~
↓
uncontrolled flow
Factory ✕
Better
Contained Lava
┌──────────┐
│ Lava │
└──────────┘
│
Path
▼
Consumer
Lava nearby does not automatically mean the consumer has a valid Heat path.
Check
Exact connection sides are only shown when they are confirmed. Do not guess a side from a diagram.
How Thermal Buffers work
Thermal Buffer is part of the Heat system; it should not be treated as a source of unlimited Heat by itself. A negative-temperature Buffer receives less heat from Lava and converts that Lava back to Cinder instead of consuming it completely.
Source
Lava
↓
Thermal Buffer
↓
Smelter
Buffer active ≠ consumer heated
A hot Buffer does not mean the consumer is heated. The final consumer must be part of a valid Heat path too.
Thermal Buffer is hot but Smelter is idle
This usually means the problem is after the Buffer.
✓ Heat source → Buffer
Now check
Reliable Smelter Heat setup
The Smelter needs a Heat path and a production path at the same time. One without the other is not enough.
Heat path
Lava
↓
Thermal Buffer
↓
Smelter
Production path
Copper
───────┤
Smelter
↓
Liquid Copper
Copper inside ≠ Smelter ready
Material path, Heat path and output path all have to be valid before the Smelter processes.
Heat available ≠ Smelter ready
Material path, Heat path and output path all have to be valid before the Smelter processes.
How to automate Heat
Move from a one-shot ignition to a contained Heat source, then to a verified burn zone. Do not assume a source is unlimited.
Tier 1 — Manual Heat
Flamethrower → material / burn zone. Useful for a test setup or small Residue work.
Tier 2 — Controlled persistent Heat
Contained Heat source → Thermal system → consumer. The reliable route for a long-running Smelter.
Tier 3 — Automated burning
Residue reaches a controlled burn zone, then Burnt Residue leaves. Gold production owns the rest of that chain.
Automated ignition · Pyro Dispenser
Repeatedly applying heat / ignition to a controlled production zone.
Useful for Residue processing.
This page does not claim Pyro is a permanent unlimited Heat source.
Use in Gold production →Heat vs Energy
Don't assume the Energy network can substitute for a Heat source. Treat Heat and Energy as separate factory systems unless a specific structure explicitly converts between them.
Heat Source
Heat system
Used by
Smelting, burning, Thermal processes
Energy
Energy
Used by
Powered tools, Steam-driven power, Synthesizer and other powered machines
✕ Energy Connector does not automatically solve Heat.
✕ Thermal Buffer is not an Energy battery.
Why isn't Heat reaching my machine?
Answer the path questions. The diagram updates as you go.
Pick what you see. The checker starts with that condition.
What isn't working?
Step 1 of 5
Is the Heat source active?
Does the Thermal Buffer / Heat path become active?
Is the consumer directly connected to the Heat path?
Does the consumer have valid production input?
Is output clear?
Your Heat path
Lava?
│
Thermal Buffer?
│
Smelter?
Likely break
Answer the highlighted question to continue the path check.
- Source
- ? Unanswered
- Path
- ? Unanswered
- Consumer
- ? Unanswered
Next
Fix the Heat source first.
Heat system ✕
Production system ✕
Why is my Lava disappearing?
Check the Buffer temperature before assuming Lava vanished. Lava contacting a negative-temperature Thermal Buffer contributes less heat and returns as Cinder.
Check
Thermal Buffer · negative temperature
+
Lava
↓
less Heat + Cinder output
+
Cinder
Cold Thermal Buffer + Lava → less Heat + Cinder. This is expected behavior, not unexplained material loss.
Contain the Cinder output and re-ignite it if your setup needs to recreate Lava.
Open Lava Guide →Useful Heat layouts
These are readable starting patterns, not a claim that one factory is optimal.
Simple Smelter
Lava
↓
Thermal Buffer
↓
Smelter
Early controlled smelting.
Shared Heat concept
Source
↓
Path
├→ Consumer A
└→ Consumer B
A shared Heat line is a concept only. It is not marked recommended until multi-consumer rules are confirmed.
Residue burn zone
Residue
↓
Heat Path
↓
Burnt Residue
↓
Gold automation.
Heat-powered production
Gold
Machine DoctorCommon Heat questions
How do I make Heat in Sandustry?+−
Use an active Heat source such as contained Lava, keep a continuous Heat path through a Thermal Buffer or equivalent setup, and attach the consumer to that path.
Why isn't Lava heating my Smelter?+−
Lava nearby is not enough. Confirm the source is active, the Heat path has no gap, and the Smelter is actually connected to that path.
What does a Thermal Buffer do?+−
A Thermal Buffer is part of the Heat path. It is not a source of unlimited Heat by itself, and a hot Buffer does not prove the consumer is heated.
Why is the Thermal Buffer hot but my Smelter isn't working?+−
If the Thermal Buffer becomes active but the Smelter does not, check the Heat path after the Buffer first. Then confirm the Smelter also has valid material input and a clear output.
Can Energy replace Heat?+−
Treat Heat and Energy as separate factory systems. An Energy network does not automatically provide Heat unless a specific structure explicitly converts between them.
Why is my Lava disappearing?+−
Lava can flow away or enter the production path. If it contacts a negative-temperature Thermal Buffer, it gives less Heat and converts back to Cinder instead of being fully consumed.
Check
Source → Path → Consumer
Most common problem: a broken Heat connection.