Stainless Steel Single-Wall Indirect Water Heaters

When aggressive water is an issue, our stainless-steel solution delivers the performance you need to fight corrosion.

Standard features:
  • Stainless Steel Heat Exchanger – Single-wall 1″ O.D. stainless steel coil. Maximum supply temperature from the boiler must not exceed 240°F.
  • Stainless Steel Tank and Heat Exchanger – Made from chromium molybdenum – titanium ferritic 444 stainless steel alloy.
  • Immersed Adjustable Aquastat – Fast acting immersion aquastat for automatic temperature control (adjustable from 80°F to 160°F).
  • Supply and Return Connections – 1″ NPT female connections are located on the front for both the boiler supply and boiler return.
  • 2″ Non-CFC Foam Insulation – Covers the side and top of tank, reducing the amount of heat loss. This results in less energy consumption, improved operation efficiencies and jacket rigidity.
  • Potable Water Connections – 3/4″ NPT factory installed dielectric fittings extend water heater life and eases installation (1″ NPT on NSS-120-L).
  • T&P Relief Valve included.
  • Steel Jacket.
  • Brass Drain/Return Valve.
  • 5 Year Limited Warranty on tank and heat exchanger.
  • AHRI Certified – Rated by the Air-Conditioning, Heating and Refrigeration institute to provide accurate performance data within the standards of the certification.  This provides a recognized standard for proper comparison of hydronic appliances.
Stainless Steel Single Wall Indirect Water Heaters
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Spec Sheet
Potable Water Connections Diagram
Model Number Capacity A.
Ht. Floor to Heater Top		 B.
Jacket Dia.		 C.
Ht. Floor to
T&P Conn.		 D.
Ht. Floor to
Water Conn.		 E.
Ht. Floor to
Cold Water
Conn.		 F.
Ht. Floor to
Exchanger
Outlet		 G.
Ht. Floor to
Exchanger
Inlet		 H.
Ht. Floor
to
Aquastat		 Aprox.
Ship Wt.
U.S. Gal. in. in. in. in. in. in. in. in. Lbs.
NSS-30-L 29 31 5/8 24 22 1/2 32 1/2 32 1/2 10 22 5/8 16 1/2 75
NSS-40-L 38 38 ¼ 24 29 1/8 38 7/8 38 7/8 10 24 3/4 18 3/4 91
NSS-50-L 50 48 24 39 3/4 48 7/8 48 7/8 10 29 1/4 19 1/2 103
NSS-75-L 73 65 5/8 24 56 1/2 66 1/4 66 1/4 10 33 5/8 19 1/9 142
NSS-120-L 111 63.375 30 1/4 65 1/2 53 1/2 2.6875 11 3/4 40 31.375 217
Model Number First Hour Delivery Rating
(Gal/ Hr.)		 Continuous Draw @ 135 F
(Gal/ Hr.)		 Stand-by Heat Loss Rating
(F/ Hr.)		 Minimum Heat Required for Ratings
(BTU/ Hr.)		 Minimum Heat Source Flow Rate
(Gal/ min)
NSS-30-L 179 160 0.8 105,000 14.0
NSS-40-L 237 209 0.6 135,000 14.0
NSS-50-L 269 229 0.5 145,000 14.0
NSS-75-L 367 307 0.4 193,000 14.0
NSS-120-L 409  319 0.3 199,000 9.0

AHRI Certified Water Heater Ratings

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