Troubleshooting: Foundry Not Working

Check the Multiblock First

Most "foundry not working" cases are structure problems. The shell must be a complete hollow rectangle of Fire Bricks with no gaps. The Foundry Controller must be on an outer face and able to see the interior. If you added a Foundry Window, make sure it's part of the wall, not floating. Break and replace the controller after any structural change so it re-validates.

Check Heat and Fuel

If the controller opens but nothing melts, you have no heat. Either add fuel to the fuel slot or place a Powered Heating Coil against the shell and give it power. A coil that isn't touching the shell does nothing. If you're using fuel, confirm the fuel slot isn't empty and that the fuel type is accepted.

Check the Output Path

Molten metal only leaves through a Foundry Drain with a Foundry Tap attached. A drain without a tap is sealed. A tap without a basin or table below it pours onto the ground and is wasted. If the tank is full and the tap is closed, the controller will stop accepting new input — open the tap or add more storage.

Check the Recipe

Not every item is meltable, and some metals require specific casts. If a cast produces nothing, try a different metal or verify the recipe in JEI/REI. Also confirm the tank actually contains the metal you think it does — mixing metals in one tank can produce unexpected alloys or block output entirely.