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Rheem GNU100-200 - GNU100-200 Universal Ultra Low NOx Heavy Duty Water Heater, Natural Gas, 199,900 BTU, 100 gallon

Item: GNU100-200
MFR: GNU100-200

This product is no longer available for purchase.

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Universal™ ultra low NOx is a family of commercial gas water heaters that are designed to fit into tight retrofit applications
  • Features & Benefits - The tighter the commercial retrofit, the more you will appreciate how the Universal's compact size and multiple water connections simplify ultra low NOx installations. Choose from 80% thermal efficiency models that range from 125,000 - 399,900 BTU/h and 82% thermal efficiency models that range from 199,900 - 270,000 BTU/h. All models have a maximum temperature setting of 180°F.
  • Space Saver Design - The short heights and narrow jacket diameters, plus the top, front and rear water inlets/outlets offer the ultimate in installation flexibility.
  • System Sentinel™ LED Diagnostic System - Our exclusive diagnostic system, with glowing LED lights, verifies system operation sequence by sequence.
  • Patented Technology - Universal's proprietary steel formulation, patented multi-flue design, combined with two coats of porcelain enamel, results in a superior heat exchanger design.
  • Ultra Low NOx Burner - The power assist burner design incorporates stainless steel multi-port burner tubes for long term ultra low NOx performance, less than 14 ng/J. A sight glass allows for burner observation. The entire design is removable and it is highly resistant to the effects of negative air pressure common in modern commercial buildings.
  • Base Rail Design - Provides for better handling when moving and positioning unit.
  • Low Profile Automatic Flue Damper - Low profile damper minimizes overall product height. Heavy duty vent hood supports are designed to withstand the rigors of installation.
  • Full-port, Full-flow Drain Valve - Factory installed brass drain valve allows for faster draining and servicing.
  • Direct Spark-to-Pilot Ignition System - Energy saving ignition that ignites pilot only when there is a call for heat.
  • Altitude Certifications - Universal ultra low NOx is certified up to 2,000 feet. High altitude certification for model GNU100-200(A) is 5,200 feet.
  • Patented Anode Rods - Anode design utilizes multiple magnesium rods to ensure corrosion resistance for a long tank life.
  • Warranty - 3-Year limited tank warranty
  • See Commercial Warranty Certificate for complete information.


NameRheem GNU100-200 - GNU100-200 Universal Ultra Low NOx Heavy Duty Water Heater, Natural Gas, 199,900 BTU, 100 gallon
Gemaire Item NumberGNU100-200
Manufacturer Product NumberGNU100-200
SKU - PIM Number1404399737011
ERP Number344682
Unit of MeasureEA
Weight780.0 Pounds (Lb)
Length30.3 Inches (In)
Width30.3 Inches (In)
Height73.0 Inches (In)
Country of OriginMEX
BTU Input199900
Ignition TypeHot Surface/Direct Spark
Capacity Gallons100
CertificationsAHRI Certified, High Altitude Certification
CompositionProprietary steel
Fuel TypeNatural Gas
Gas TypeNatural Gas/LP
Maximum Pressure (PSI)150
Maximum Temperature180°F (82.2°C)
TypeTanked - Gas
Warranty OfferedYes
Energy Star RatedNo
UL ListedNo
Product FamilyGNU100
GEM - Case Quantity


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