ProLine® XE Tankless Condensing X3 (100 series)

The ATI-540HX3-N tankless water heater uses up to 199,000 BTU/hr of natural gas to deliver an endless supply of hot water for a 3 bath home in northern climates and up to a 4 bath home in southern climates (one shower head per bath).

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Maintenance & Troubleshooting
Maintenance

Condensing Tankless with X3® Technology - Cartridge Installation

Troubleshooting

Condensing Tankless with X3® Technology - 111 Ignition Failure

Condensing Tankless with X3® Technology - 121 Loss of Flame

Condensing Tankless with X3® Technology - 991 Imperfect Combustion

Marketing Videos
Condensing Tankless with X3 Technology - How It Works
Condensing Tankless with X3® Technology - Application and Installation
Condensing Tankless with X3® Technology - Features and Benefits
Take advantage of market incentives with ENERGY STAR® A.O. Smith water heaters