I can't stop lava from freezing into stone, and I can't even stop it with heaters.
I'm trying to make Yellow Stone....
Yes, Yellow stone is a supervolcano.. which is why I need lava.
Few tips:
Maybe you have ambient heat on? Turn it off.
You can store LAVA in PIPE (releasing process might be slow)
Use FRME as wall (FRME doesn't conduct heat)
Use plasma to heat LAVA (might not look cool)
Use CRAY to produce LAVA instantly (you can set any temp. on it)
Use different methods to isolate LAVA, so it won't lose heat.