A.O. Smith Signature GT15TM-199X3-N Gas Tankless Water Heater 39.7 L/min

Name: A.O. Smith Signature GT15TM-199X3-N Gas Tankless Water Heater 39.7 L/min
Brand: A.O. Smith
SKU: 5015680677
Price: 868.45 USD
Availability: InStock

$868.45 $1,579.00

Taxes included. Shipping calculated at checkout.

The A.O. Smith Signature condensing gas tankless water heater delivers dependable, on-demand hot water with a maximum flow rate of 39.7 L/min. Engineered with patented X3 Scale Prevention Technology, it resists scale build-up in hard water conditions to extend operating life up to three times without requiring annual descaling.

Featuring primary copper and secondary stainless steel heat exchangers, this unit provides durable and quiet 51 dB operation. Built-in freeze protection down to -20.6°C and flexible indoor or outdoor wall-mount installation support robust whole-home performance.

Key Features

Brand	A.O. Smith
Model Number	GT15TM-199X3-N
Product Type	Tankless
Fuel Type	Natural Gas
Installation Type	Wall Mount
Use Location	Indoor / Outdoor
Maximum Flow Rate	39.7 L/min
Uniform Energy Factor	0.95
Noise Level	51 dB
Voltage	120 V
Water Connection Size	3/4"
Height	102.6 cm
Width	43.5 cm
Depth	30.1 cm
Weight	37.6 kg
Vent Type	PVC / ABS / CPVC

Highlights

Delivers powerful on-demand hot water with 199,000 BTU for reliable whole-home performance
Patented X3® Scale Prevention Technology eliminates the need for annual descaling and extends unit life up to three times versus an unprotected heater.
Electronic ignition and a quiet 51 dB operation keep performance seamless and unobtrusive
Supports flow rates up to 10.5 GPM, with activation at just 0.4 GPM for fast, efficient performance.
Flexible installation indoors or outdoors, with venting compatible with PVC, CPVC, Polypropylene, or solid-core ABS pipe.
Backed by a 15-year limited warranty on the heat exchanger and a 5-year limited warranty on parts for residential use.
Primary copper and secondary stainless steel heat exchangers built for lasting durability
Built-in freeze protection rated to -5°F keeps the unit running in harsh climates

Compatibility

Compatible with natural gas supplies and approved venting materials including PVC, CPVC, Polypropylene, and solid-core ABS pipes. Features a 3/4-in water connection.

Warranty

15-year limited warranty on the heat exchanger
5-year limited warranty on parts for residential use

Downloads

Frequently asked questions

Can this water heater be installed outdoors?

Yes, this unit is designed for flexible installation both indoors and outdoors.

Does this model require annual descaling?

No, the patented X3 Scale Prevention Technology prevents scale build-up and eliminates the need for annual descaling.

What type of venting is compatible with this unit?

Venting is compatible with PVC, CPVC, Polypropylene, or solid-core ABS piping.

What is the minimum operating temperature for freeze protection?

The built-in freeze protection protects the unit in cold weather down to -20.6°C.

Made with care

Great value

Elegant design

Quality materials

This product is crafted with quality materials to ensure durability and performance. Designed with your convenience in mind, it seamlessly fits into your everyday life.

Orders typically ship within 5–7 business days. Returns are accepted within 30 days of delivery — see our Shipping Policy and Refund & Return Policy pages for full details.