Xtreme™ is a family of high-input, fast recovery commercial water heaters that complies with Low NOx Emissions

Features & Benefits

Xtreme is an advanced line of fast recovery commercial gas water heaters. These products can deliver up to 756 gallons per hour at 100 degree F rise. The small jacket diameter makes it a popular choice for retro fits and it is a versatile choice for new construction. Models range from 500,000-715,000 Btu/h, with a maximum temperature setting of 180 degrees Fahrenheit.

Space Saver Design

Xtreme maximizes installation adaptability by offering models with front and rear inlet/outlet water connections. Short heights and small jacket diameters result in greater installation flexibility.

System Sentinel™ LED Diagnostic System

Our exclusive diagnostic system, with glowing LED lights, verifies system operation sequence by sequence.

Patented Multi-Flue Tank Design

Proprietary steel formulation, patented multi-flue design, and two coats of high temperature porcelain enamel maximize corrosion resistance and result in a superior heat exchanger design.

Automatic Flue Damper

Low profile design minimizes overall product height. Heavy duty vent hood supports are designed to withstand rigors of installation.

Specialized Burner Assembly

Each model features five premix burners mounted into a metal face plate and sealed with a Viton gasket. Patented “quick release” manifold for easier service.

Direct Spark-to-Pilot Ignition System

Energy saving ignition that ignites pilot only when there is a call for heat. Round Premix Burners Precision burners are formed from high chromium stainless steel.

Low NOx Emissions

GX90-550 and GX90-640 meet Low NOx emissions of less than 40 ng/J.

Full-port, Full-flow Drain Valve

Factory installed brass drain valve allows for faster draining and servicing.

Altitude Certifications

Standard Natural and LP models are certified up to 2,000 feet. High altitude models, 8,000 feet.

Anode Rods

Patented design utilizes multiple magnesium rods to ensure long life and corrosion resistance.

90 GX90-550(A) 550,000 NAT
90 GX90-640(A) 640,000 NAT
90 GX90-715(A) 715,000 NAT
90 GX90-500(A) LP 500,000 LP
90 GX90-600(A) LP 600,000 LP
90 GX90-680(A) LP 680,000 LP

(A) Indicates available ASME mode

  • High-input – 550,000 - 715,000 BTU/hr.
  • Available in 90 gallon capacity
  • Space-saving tank design
  • Low profile automatic flue damper


Brochure (US)
Revit Model (GX90, 500, 715)
Specification Sheet (US and Canada)
Use and Care Instructions (US and Canada)
Warranty Information (US)


United States
Tank Warranty - 3 Years
Parts Warranty - 1 Year

Tank Warranty - 3 Years
Parts Warranty - 1 Year

KwikComfort® Financing can help make your purchase even easier.
Rheem makes it easy to find a financing option that works for you! With many options and benefits available, KwikComfort Financing is the best way to get the home comfort you need without the wait.

  • Applications made easyWe'll help you avoid lengthy contracts, headaches and hassles.
  • Kwik credit decisionsYou'll get an answer to your application within minutes.
  • Fast credit for the futureFinance your Rheem equipment and anything you want to add later.
  • Reduced interest/fixed paymentsGet low interest and fixed monthly payments until the purchase is paid.
  • Minimum monthly paymentTake advantage of convenient monthly payments that fit your budget.
  • Deferred interest/no interestEnjoy interest-free payments as long as the balance is paid by the due date.