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Apartment Building DHW

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A small apartment building currently has an A.O. Smith Burkay 120,000 BTU boiler directly heating a 75 gallon storage tank (not an indirect) and the boiler needs to be replaced. That boiler doesn't seem to be made anymore and it would be nice to use the existing 6" flue rather than going high efficiency PVC up the side of the building. Any suggestions for a replacement boiler?

Since the Burkay has no storage, it's short which helps with the flue run. It's basically a copper heat exchanger sitting on top of a flame.

8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

Two btu per sq ft for degree difference for a slab

Comments

  • hot_rod
    hot_rod Member Posts: 28,271

    a copper tube boiler from Lochinvar, RBI, Raypack with a plate HX and use the existing tank. Similar to the EK system.

    How old is the tank? EK builds the package to connect to any boiler.

    No way to fish a mod con flex vent up the 6"

    Screenshot 2026-09-23 at 4.03.54 PM.png
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream