Blessed Furnace - TheUnderTaker11/KitchenSink GitHub Wiki

This is a furnace that doesn't need fuel to run. All you have to do is put a lava block adjacent to the furnace and it will smelt an item every 2 seconds. The more lava blocks you put around the furnace, the faster it will go. Covering all 6 sides will make it smelt 1 item every tick. (A tick is 1/20th of a second)

Items can be pulled out the bottom and right side of the block, and input on any other side.

(Added version 1.16)