GU100 Eternal Condensing Hybrid Water Heater

GU100 Eternal Condensing Hybrid Water Heater


Warning:  This unit produces less hot water where incoming ground water is very cold.  Please consult with a professional before purchasing to make sure that this unit will be powerful enough for your use.  We do not refund any units that are undersized.


Eternal GU100 is the affordable and flexible alternative to traditional tank water heaters in retrofit applications. With the hybrid, you get endless hot water with minimal pressure drop and 96% thermal efficiency. Its lightweight compact design, 1/2” gas line capability, top mounted water connections, and PVC venting allows for easy installation in any home.

• 100% Stainless Steel Heat Exchanger w/built in reserve tank
• Full flow design does not restrict water flow
• Dual Activation (Temperature and Flow Sensing) is compatible with low flow Water Sense fixtures
• 2” or 3” PVC Venting eliminates costly materials required by tankless units
• Flexible NG / LP / Indoor / Outdoor / Direct Vent / Power Vent conversions in one unit
• Quick-Connect / Clip-On components makes service easy for technicians
• Patented self-cleaning utilizes turbulent flow to flush sediments out
• Digital display for easy temperature adjustment and diagnostics

• Endless hot water, up to two simultaneous domestic applications without pressure drop
• 94% Thermal Efficiency saves cost, 0.94EF exceeds Energy Star, and qualifies for available government and/or local utility rebates
• Meets new Ultra Low Emissions standard (SCAQMD 1146.2 Listed) leaves almost no carbon footprint
• Easy integration into existing recirculation system and no startup lag eliminates cold water sandwich


Only requires 1/2" gas line


Designed for up to 2-1/2 bathrooms if the incoming water is not too cold (less bathrooms for northern areas).  Please see our GU195(S) model for a larger model.


Free shipping via UPS ground (3-5 business days)


15 year Residential Warranty


  • Item #: GU100
  • Manufacturer: Eternal
  • Manufacturer's Product Number: GU100

GU100 Eternal Condensing Hybrid Water Heater

Price: $1,099.00
Availability: Out-of-Stock
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