The boiler has been running for a few months now and it can heat (we have burned 6 cords which is all we set aside for this winter)! These two video updates from Tuna demonstrate the latest. Summary: the boiler can heat the cabin in addition to the pavilion (if we burn lots of wood).
Two months later, test # 2. Not only can it heat multiple buildings, it doesn’t burn as much wood after some programming changes!
You can see the photo/video album of the project here: https://www.icloud.com/sharedalbum/#B0f5n8hH4GTJMha