Mills 20 boilers — Heating Help: The Wall
I have the data sheet for the Mills 2000, which is the later version of the 20, set up for oil firing without the lower firebox. The 7 section is 44" long and 28.5 " wide. The two top supply tappings are 36 1/8" apart. Ratings are as follows: Oil GPH 4.45. Gross output 484 MBH. Steam net 1515 Sq. Ft EDR.