The Eternal GU100 is an affordable and flexible alternative to traditional tank water heaters in retrofit applications. The hybrid model features endless hot water, while a small reserve tank inside the unit maintains water pressure and avoids temperature fluctuations. The unit is 96% thermal efficient, has a lightweight compact design, 1/2” gas line capability, top-mounted water connections, and uses 3” PVC venting. The GU100 can replace a traditional 50-gal. standard tank, is compatible with most recirculation systems to deliver instant hot water and comes with a 15-year residential no-leak warranty.