The 140 Series offers high efficiency Ultra-Low NOx condensing technology allowing for the use of 3 PVC venting and has 0 clearance to combustibles. Remote control included as a standard feature. Indoor models are certified up to 10,100 ft. altitude. Provides a variety of installation options: indoor, outdoor and direct vent. Complies with Ultra-Low NOx regulations and meets the energy efficiency requirements of ASHRAE 90.1b-1992. The GTS-140-NIH tankless water heater uses up to 120,000 Btu/hr of natural gas to deliver a max flow rate of 6.6 GPM. It utilizes condensing technology to achieve an Energy Factor of 0.93, and is ENERGY STAR qualified. This model meets Low NOx emission requirements, and comes with a 15-year limited warranty.