That would be idleing most of the time I’m sure, since there would be litte demand. I had closed cell foam put in, and that makes a mighty tight house. Tonight will be in the teens, so tomorrow we’ll see how it did overnight. I couldn’t fill it up, for fear of overheating. I went over this afternoon and tied 16’ of fin tube into the supply and return with an automag zone valve. I just left this open, so anytime the boiler pump is running the water will run through that. If the radiant zone needs heat (I left the thermostat at 50) the main circ will pull water to it. Still, I only left the wood up to the bottom of the door. If the fire goes out that is better than a boil over.
Question....my gravity overheat loop is higher than the rest of the system by a few inches, including my air separator. I put a drain coupling (little screw thingy) up there to purge out the air when I filled it, but there were still some bubbles in the system. Will this little loop tend to capture air? I plan to put the automag on a switch so I can use this overheat loop to heat my shop area in the basement, so it will get used from time to time. When the main circ runs I assume this air will get purged by the main separator. I didn’t have time to stick around and find out.