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GNU100-200 Rheem 100 Gallon Ultra Low NOx Heavy Duty Commercial Water Heater
GNU100-200 Rheem 100 Gallon Ultra Low NOx Heavy Duty Commercial Water Heater

Our Price: $5,190.00

Availability: Usually Ships Same Day if Ordered by 2:00PM Pacific Time. Shipping Fees are Calculated at Checkout
Product Code: GNU100-200

Gas Options

Choose the GAS option*:


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.

Innovative Technology

  • Universal’s proprietary steel formulation, 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

  • GNU100-200(A), -250(A), -270(A) models are rated up to 5,200 feet.
  • GNU100-200(A) HA, -250(A) HA, -270(A) HA model High Altitude variants are rated up to 10,100 ft above sea level.
  • All other models are rated to 2,000 feet.

Anode Rods

  • Anode design utilizes multiple magnesium rods to ensure corrosion resistance for a long tank life.


  • 3-Year limited tank warranty

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