EFM Highboy

How many gallons of water does theFittsgibbon boiler hold.And when buying a new boiler how critical is the capacity in gallons.
Thanks Ashman

I'm told 74 gal.

I believe the number is ~54 gallons. If you don't have a lot of mass or water volume in your radiation, I doubt you would notice a difference from an extra 14 gallons (Highboy vs normal 520) of boiler capacity. That said, the Highboy units are very well made. You WILL notice a difference when comparing an EFM 520 compared to a low mass gas or oil boiler.

-Rob

Sorry Glenn, but I vote with Rob on the capacity. I think that 74 gallon figure came from a post by coal berner a few years ago that he eventually corrected.

I'm not a boiler design specialist, but I think the larger water capacity provides a reservoir of extra btu's that supports greater DHW production (Highboys normally shipped with 7 gpm coils; regular 520's shipped with 5 gpm coils). Also, it's my understanding that the increased water capacity resulted from the increased height of the boiler, which reflected a lengthening of the firetubes and an increase in the heat exchange area and efficiency of the Highboy relative to a normal 520.

Mike

I believe that you are both right!
I was thinking of coalburners post but didn't see the adjustment. I always thought that 74 seemed to be quite a large number compared to the height difference of only 8"!

I stand corrected!

54 is my final answer!


Glenn

1948 to 1955 High boy 520 hold 54 gals of water 7 GPM water coil came standard with them 5 GPM or 7 GPM can be used like with any of the efm boiler tops .

AP-1 520 held 40 to 41 Gals of water depending on who made them and if they are a tube boiler or flat plate heat
exchange boiler top.

AP-1 350 held 30 to 32 Depending on SQ top or round top and if a tube or flat plate heat exchanger .
The Sq top boiler was made from 1960 to 1973 The Round top was never stamped with year or Manufacturer only code / inspector stamped . Lo Line boiler company made most if not all of the 350 boiler tops

AP-1 700 held 73 to 74 Gals again depending on tube or flat heat exchanger made until 1974 for efm

AP-1 900 held 94 Gals last year made 1986 for efm

AP-1 1300 held 120 gals of water last year made 1986 for efm