Mine does not heat anything either. Wish it did though. I would love to have unfrozen water.Jeff -
Mine definitely doesn't increase temperature but it is composting nicely.
I think part of the heat generation with DarkMatter's coop is that it is partly BELOW GROUND LEVEL if I understand correctly - I think he said he dug down to make a pit. That would immediately help with raising temperature I'm thinking.
Also - I'm heading down to AutoZone for that pad heater later this morning. Going to try the 60 watt 8.5 x 5.5 right on the cup necks to see if that will keep them open. We're back in the teens again.

Today it's in the 20s. Yesterday it was so nice and warm, that the yard was disgusting mud, ice and poop. I forgot how much I hated thaws. Mud is slipperier than ice!