Just finished the install of a 1980 DF520 in my brother's house. Four zones of baseboard in the house, radiant heat in the basement floor. ~4000 sq. ft total, running buck size coal through a 60" auger pipe...no coupling. 7 gpm coil, "Fuel Smart" Hydrostat for the aquastat...adjusts the boiler temperature based on load. Seems to be working very well so far. Many thanks to Dave O'Neil and forum member Pacowy for the boiler.
How about a little tutorial on how you used the hydrostat and how it is set up to adjust the temps. How did you calculate the temp difference per load? I went to the website but it was not very informative about the unit.
I just followed the directions and set the # of zones to 5. The big thing is setting the jumper switch to "I" for indirect...that allows a ZR signal (timer) to bypass the economy feature and run normally.
By that you mean the idle timer operation? I assume the unit is somehow settable for the temp at 1 zone, 2 zones, etc. Otherwise how would it know what is the correct temp unless the loads were always made the same. In all situations.
It has an adjustment for the "economizer" setting...they recommend you set the dial to the number of zones in the system...6 is the max. I guess it keeps track of how many heat calls there are and how long they last...and how the boiler temperature reacts.
Ahhhh, so it kind of learns abut the loads of each zone? Wow, that would be great. I wonder how it works with the outdoor reset unit? I will have to explore that some more. So far, the info online is terrible.