5 years Limited

Rustproof because water comes in contact with nothing but copper, brass or bronze|Copper transfers heat eight times faster than ferrous metals yet offer remarkable structural strength without excessive weight|Free from the effects of thermal shock|Efficient copper coil combustion chamber|Continuous coils of tightly wound copper tubing form a unique combustion chamber|Water circulating thru the coils, around the flame, captures radiant heat which may otherwise be lost|High efficiency stainless steel burner developed especially for A.O. smith water heaters using the very latest burner principles|Forced water circulation improves system efficiency|Water moving at 2 to 4 ft per second helps to prevent lime buildup and also scrubs extra heat from the copper coil combustion chamber|Proven pilot ignition system provides flame failure response in less than one second|Redundant high limit controls and gas valves assure safe shutoff in the event of overheating or flame failure|Requires 120 V 60 Hz, maximum inlet gas pressure of 14 in W.C and activation of heater by external temperature control|Jacket: Prefinished with a bonderized coating followed by a baked on enamel finish|All models are design-certified by CSA international, according to ANSI Z21.10.3 - CSA 4.9 standards governing circulating water heaters|Models are ASME certified and are design-certified by NSF international to NSF sanitation 5|Models meet the thermal efficiency and standby loss requirements of the U.S department of energy and current edition of ASHRAE/IESNA 90.1

ASME Certified|CSA Certified|NSF Approved|Star Design Certified