Volcano Steam Turbine Help

[PuffyB]

Im trying to utilize the heat from a copper volcano to run my steam turbine but it somehow is too cold.
The idea is to let the heat transfer through the doors to my steam turbine, and then once its hot enough the doors open(creating a vaccuum) and the doors to the wheezeworts close, cooling the steam.

But for some reason the heat from the volcano isnt even enough to evaporate the PO2 in the first place, nevermind getting to 230 degrees to run the turbine. The volcano room seems to cool down substantially between eruptions, so the heat isnt ever building up

Any ideas what the problem could be?
The insulated tiles are ceramic, the doors are gold amalgam, metal tiles are iron, the tempshift plates are copper

[Craigjw]

That looks like a LOT of mass to heat and you're actually not providing that much heat from a metal volcano.  Give it a few thousand cycles and you might boil the water.

[storm6436]

Yeah, if you're going to try that with a metal volcano, iron is a much better choice.   Per unit mass, iron carries something like 3x or 4x the energy per unit mass per degree temp than copper or gold, IIRC.