Difference between ProLine, ProLine Master and ProLine XE series
ProLine standard series - includes water heaters with 6-year warranty and all the basic AO Smith component features listed below. ProLine Master series - are the same as "standard" series, except for 8 year warranty and a (possible) difference in the number, material or size of the anode rods. ProLine XE series - are high-end, ultra-efficient Energy Star listed water heaters, with longest warranty (6 or 10 yrs depending on the model), electronic controls, additional safety features, PVC venting options on select models, as well as the best anode rods in the lineup.
AO Smith water heater features
The following features are standard on most models - check individual product description for details.
CoreGard - innovative anode rod protection which integrates a stainless steel core wire into the sacrificial anode and helps to keep it intact, effectively extending it’s life and water heater protection.
Intelligent gas control (gas models only) - with millivolt technology (no external power supply needed), piezo igniter and external LED for easy diagnostics and troubleshooting.
Blue Diamond glass coating - uses advanced, commercial grade coating which is superior to standard glass coating used for tank lining (to protect it from corrosion).
DynaClean automatic sediment cleaning - reduces accumulation of sediment and helps to improve long-term performance and energy efficiency of the water heater.