A: Traditional tanks can supply hot water to as many applications as needed; however, the problem is running out of hot water over time. Tankless can supply endless hot water but does not have the capacity to satisfy multiple applications in a busy household. The Hybrid approach delivers the best of both worlds: capacity for many applications for as long as you like.

A: Aside from the built-in storage, Eternal has dual mode activation which mimics operational characteristics of both tank and tankless. At under 0.5gpm, Eternal has fixed gas input rate and is activated by thermostat, and at above 0.5gpm, Eternal has full modulated gas input rate and is activated by flow sensor. The Hybrid design eliminates the minimum activation problem commonly associated with tankless.

A: Eternal has much higher efficiency and stores up to just 6.4 gallons of hot water; its compact and efficient design enables capacity to replace multiple tanks, but uses less energy than a standard 50 gallon gas water heater.

A: Eternal is constructed with corrosion resistant stainless steel that requires no maintenance; tankless is made from soft copper which can clog and corrode with use. Tankless requires costly periodic flushing of heat exchanger with vinegar to ensure performance and longevity whereas Eternal is engineered with a patented self cleaning design.

A: Eternal utilizes an advanced multi-pass design that harnesses and recycles combustion heat; by wasting less heat the Eternal Hybrid™ is more efficient. The small storage also provides a tempering buffer that doesnt work the heating system as hard; thus providing much higher capacity.

A: There are 4 key benefits to the patented Eternal Hybrid™ system.

• Unlike tankless water heaters that have to convert incoming cold water to hot every time you open a tap, the Eternal Hybrid™ preheats the cold water in the reservoir so its easier to create hot water from warm water. Analogous to automobile acceleration, it is easier to reach 60mph from 30, rather than from a dead stop.
• On-demand tankless water heaters cannot be used with water saving recirculation systems unless a small storage tank is plumbed with the tankless. However, adding a small storage tank to tankless is labor intensive and inefficient. Eternal Hybrid™ has all the necessary components to be installed in a recirculation system straight out of the box. In addition, Eternal's warranty is not reduced when used with domestic recirculation systems.
• Tankless systems are prone to "cold water sandwiching" a problem which can be shocking to unsuspecting bathers. Tankless is flow activated and every time the hot tap turns on and off, the heat exchanger resets and flushes with cold water. For example, you use hot water at the sink next to the shower, and jump into the shower after turning off the sink faucet. Two minutes into the shower, you will experience a jolt of cold water as the tankless is flushed. Eternal Hybrid™ design eliminates this problem.
• Eternal is installed in an easier fashion similar to tanks. The water connections are on top of the unit, and the T&P Relief is to the side. Eternal can run on as low as 3.5" WC of Natural Gas, and is PVC vented. Tankless units generally require 5-6" WC Gas Supply, and expensive proprietary venting kits.

A: Counter Physics! Standard tanks collect sedimentation at the bottom because of gravity with water entering in a top-down fashion. Eternal utilizes a patented "counter flow design" where water enters the tank from the bottom-up. The sedimentation is constantly stirred and carried out of the tank.

A: In 1999, the Grand Hall President and his engineering team began research and development of a tankless style water heater for Asia, Europe, Australia and US markets. After several prototypes and testing, it became apparent the inherent design limitations of a tankless water heater would not meet the needs of America's busy households. The team went back to the drawing board and in 2003 engineered the world's first hybrid water heating system. After 3 years of US field testing to ensure performance and reliability, in 2006 the Eternal Hybrid™ was available for sale through the plumbing trade.

A: Proper gas, water and air supply is needed for Eternal to perform correctly. The gas line must be sized sufficiently to carry the BTU load of all gas appliances. Water connection is standard 3/4" for cold inlet and hot outlet. Combustion air is needed for all indoor power vented models.

A: Eternal Hybrid™ is a Category III (Positive Pressure Non-Condensing) appliance, and Eternal Condensing Hybrid is a Category IV (Positive Pressure Condensing) appliance. This means that the venting must be airtight to prevent leakage of exhaust gases into living space. Because Eternal emits very low exhaust temperature as a highly efficient appliance, plastics such as Schedule 40 PVC, CPVC, and ABS should be used.

A: Yes. The built-in storage makes Eternal ideal for a closed loop system.

A: Eternal does store hot water and when installed outdoors, can withstand freezing temperatures down to -4F; however, the protection against freezing only works when electricity and gas are supplied. Should your area be prone to service interruptions, please do not install Eternal outdoors.

A: Eternal is ANSI/CSA Z21.10.3 Ð 2004, IAPMO/UPC, SCAMQD 1146.2 and tested with D.O.E. standards. Eternal is registered with the California Energy Commission and listed with CSA International Laboratories.

A: Eternal is designed to maintain flow as a priority; therefore, when heating capacity is exceeded, the outlet temperature may be lowered. For instance, GU32 set at 122°F with 5 showers running may drop the outlet down to 116°F should a 6th shower be opened.

A: No. Eternal uses an electronic direct spark ignition system that is computer controlled. This system is proven and reliable with over 10 years of accelerated stress testing in our labs.

A: Yes. During vacations or long business trips when the Eternal will not be used, simply press the power button to turn off the unit. Upon your return, just push the same button again to turn the unit back on. Unlike tank type water heaters which take a long time to recover, the Eternal will reboot and bring water right back to temperature within minutes.

A: Yes. Eternal can be used generally where standard tanks are spec'd. Grand Hall can supply plumbing diagrams for ideas and may offer limited engineering support depending on the complexity of the project. We strongly recommend contacting us ahead of project to plan and review accordingly.

A: Yes. Professional installation is required for proper performance and warranty.

A: Eternal utilizes a premixed injection combustion process which is more efficient and clean. The system has a turbo fan that takes air and mixes it with fuel, which is then pressure injected into the sealed chamber for combustion. Because the air to fuel ratio is always perfectly mixed, Eternal emits near zero greenhouse gas emissions and delivers better heat output than conventional processes.

A: Exhaust gas carries wasted heat into the atmosphere. An efficient appliance will use more heat and have less exhaust. Eternal has an exhaust temperature as low as 120°F (which is safe to touch), and carries much less wasted heat than either tank or tankless heaters.

A: Yes. Eternal Hybrid™ uses a "straight through" water flow design so hot water is produced quickly and without the pressure loss associated with coiled copper heat exchangers. Tankless units slow the path of water in order to transfer heat and this restricted flow can conflict with some newer valves.

A: Yes, for after hour emergencies call the Eternal Technical Support 24/7 Hotline at 1-866-946-1096.