A. O. Smith Adapt™ Tankless Water Heaters
High-Performance Condensing Gas Tankless Water Heaters
Never Descale Again. Ever.
X3™ Scale Prevention Technology protects the heat exchanger by preventing scale buildup before it starts, extending the life of the unit without the need for regular descaling or maintenance.
✔️ Protected❌ Unprotected
?️ No Annual Descaling? Scale Buildup
Saving you money year after year! Up to $250-$350 every year in descaling service.
Designed for Canadian Hard Water.
Tested in Canadian conditions, Adapt™ Tankless Series with X3™ technology resists scale buildup making them ideal for hard water environments.
Map of Canada illustrating water hardness levels: Slightly Hard Water (0.6-3.6 gpg), Moderately Hard Water (3.6-8.6 gpg), Hard Water (8.6-14.4 gpg), Very Hard Water (14.4+ gpg).
Lasts 3x Longer!
Engineered for long-lasting performance, our Adapt™ tankless series delivers peace of mind for years to come. *Compared to other tankless models without X3™ Technology.
Why Go Tankless?
Space Saving
Tankless water heaters are compact and wall-mounted, freeing up floor space and making them perfect for smaller homes, condos, or utility closets.
Endless Hot Water
Never run out of hot water again! Tankless units provide a continuous supply, ideal for families or back-to-back showers and laundry.
Lower Energy Bills
Because they heat water only when needed, tankless systems use less energy than traditional tanks—helping reduce your monthly utility costs.
Better Warranty
Built to last, backed to perform! NO hard water exclusions!* (*X3™ models only)
Adapt+ Premium Condensing Gas Tankless Water Heater
Featuring industry-unique single stainless steel heat exchanger and integrated recirculation pump.
- ✔️ X3 Scale Prevention Technology
- ✔️ Integrated Recirculation Pump: Cuts wait time! Provides faster hot water delivery.
- ✔️ Built-in Electronic Control Display
- ✔️ Single Stainless Steel Heat Exchanger: Industry-unique feature with minimal welds that reduce scale build up.
- ✔️ 2" or 3" Venting
- ✔️ Field Conversion Kit: Included propane conversion kit provides installation flexibility.
Models include ATHR-160M, ATHR-160X3, ATHR-180M, ATHR-180X3, ATHR-199M, ATHR-199X3. X3™ Scale Prevention Technology can be added at any time (optional accessory) for M models.
Adapt SC Standard Condensing Gas Tankless Water Heater
- ✔️ X3 Scale Prevention Technology
- ✔️ Built-in Electronic Control Display
- ✔️ Primary Copper Heat Exchanger
- ✔️ Secondary Stainless Steel Heat Exchanger
- ✔️ 2" or 3" Venting
Models include ATM-160X3-N, ATM-180X3-N, ATM-199X3-N.
User-Friendly Digital Interface
Designed for control and monitoring, the display provides real-time system status, including water flow detection, pump activity, flame presence, and standby mode.
Diagram shows a digital display with buttons labeled A through M. A table lists the function of each button: A (Water Flow Detected), B (Pump is Operating), C (Flame Detected), D (Pump Timer 1 & 2 Active), E (Pump Button), F (Time Button), G (Up & Down Buttons), H (Operation Button), I (Setting Button), J (Pump Timer ON/OFF Indicators), K (Standby Mode), L (Time & Pump Timer Setting), M (Display).
Faster Hot Water When You Want It.
Smarter, more efficient, and more user-friendly.
Integrated Recirculation Pump
Circulates hot water through plumbing loop for faster hot water delivery. (Adapt™+ models only)
Remote Recirculation Kit
Wireless button or sensor that triggers the recirculation pump. (Adapt™+ models only)
Wi-Fi Module Kit
Enables remote control and monitoring via smartphone app. (Adapt™+ models only)
Specifications
| Series | Model Number | X3™ Scale Prevention | Wi-Fi Connectivity | Recirculation Pump | Input Rate (Min. BTU/h - Max. BTU/h) | Fuel Type | Heat Exchanger(s) | Uniform Energy Factor (UEF) | NOx Emissions | Maximum Flow Rate** | Activation Flow Rate | Continuous Fire Flow Rate | Water Pressure Min. - Max. | Simultaneous Shower Usage | Supply Gas (NG) Min./Max. in W.C. (kPa) | Supply Gas (LP) Min./Max. in W.C. (kPa) | Hot/Cold Connections | Gas Connection | Temperature Settings Min. - Max. | Ignition System | Power Supply | Sound Level*** | Elevation | Freeze Protection | Cascade | Venting Type | Venting Size, Max Run | Venting Material | Height | Width | Depth | Weight | Warranty Heat Exchanger | Warranty Parts |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ADAPTTM+ Premium | ATHR-160M | Optional | Optional Module Kit | Optional | 9,000 - 160,000 | Natural Gas (Field Convertible to LP) | Single Stainless Steel | 0.95 | Ultra Low NOx | 10.5 GPM | 0.4 GPM | 0.26 GPM | 15-150 PSI (40 PSI Rec.) | 2.5 Showers | 3.5 (0.9) / 10.5 (2.6) | 8.0 (2) / 13.0 (3.2) | 3/4" NPT | 1/2" NPT | 100°F - 140°F (38°C-60°C) | Electronic Ignition | 120V, 50/60Hz, <5A | 50.3 dB | Sea Level to 10,100' (3,078.5 m) | -5°F (-21°C) | Up to 12 units | Power Direct Vent | 2", 75' (5cm, 22.9m); 3", 150' (8cm, 45.7m) | PVC, CPVC, Polypropylene | 33.8" (86 cm) | 16.5" (42 cm) | 16.1" (41 cm) | 104 lb (47 kg) | 15 years | 5 years |
| ADAPTTM+ Premium | ATHR-160X3 | Integrated | Integrated | Integrated | 9,000 - 160,000 | Natural Gas (Field Convertible to LP) | Single Stainless Steel | 0.95 | Ultra Low NOx | 10.5 GPM | 0.4 GPM | 0.26 GPM | 15-150 PSI (40 PSI Rec.) | 2.5 Showers | 3.5 (0.9) / 10.5 (2.6) | 8.0 (2) / 13.0 (3.2) | 3/4" NPT | 1/2" NPT | 100°F - 140°F (38°C-60°C) | Electronic Ignition | 120V, 50/60Hz, <5A | 50.3 dB | Sea Level to 10,100' (3,078.5 m) | -5°F (-21°C) | Up to 12 units | Power Direct Vent | 2", 75' (5cm, 22.9m); 3", 150' (8cm, 45.7m) | PVC, CPVC, Polypropylene | 41.8" (106 cm) | 16.5" (42 cm) | 16.1" (41 cm) | 104 lb (47 kg) | 15 years | 5 years |
| ADAPTTM+ Premium | ATHR-180M | Optional | Optional Module Kit | Optional | 10,000 - 180,000 | Natural Gas (Field Convertible to LP) | Single Stainless Steel | 0.95 | Ultra Low NOx | 10.5 GPM | 0.4 GPM | 0.26 GPM | 15-150 PSI (40 PSI Rec.) | 2.5 Showers | 3.5 (0.9) / 10.5 (2.6) | 8.0 (2) / 13.0 (3.2) | 3/4" NPT | 1/2" NPT | 100°F - 140°F (38°C-60°C) | Electronic Ignition | 120V, 50/60Hz, <5A | 50.3 dB | Sea Level to 10,100' (3,078.5 m) | -5°F (-21°C) | Up to 12 units | Power Direct Vent | 2", 75' (5cm, 22.9m); 3", 150' (8cm, 45.7m) | PVC, CPVC, Polypropylene | 33.8" (86 cm) | 16.5" (42 cm) | 16.1" (41 cm) | 104 lb (47 kg) | 15 years | 5 years |
| ADAPTTM+ Premium | ATHR-180X3 | Integrated | Integrated | Integrated | 10,000 - 180,000 | Natural Gas (Field Convertible to LP) | Single Stainless Steel | 0.95 | Ultra Low NOx | 10.5 GPM | 0.4 GPM | 0.26 GPM | 15-150 PSI (40 PSI Rec.) | 2.5 Showers | 3.5 (0.9) / 10.5 (2.6) | 8.0 (2) / 13.0 (3.2) | 3/4" NPT | 1/2" NPT | 100°F - 140°F (38°C-60°C) | Electronic Ignition | 120V, 50/60Hz, <5A | 50.3 dB | Sea Level to 10,100' (3,078.5 m) | -5°F (-21°C) | Up to 12 units | Power Direct Vent | 2", 75' (5cm, 22.9m); 3", 150' (8cm, 45.7m) | PVC, CPVC, Polypropylene | 41.8" (106 cm) | 16.5" (42 cm) | 16.1" (41 cm) | 104 lb (47 kg) | 15 years | 5 years |
| ADAPTTM+ Premium | ATHR-199M | Optional | Optional Module Kit | Optional | 10,000 - 199,000 | Natural Gas (Field Convertible to LP) | Single Stainless Steel | 0.95 | Ultra Low NOx | 10.5 GPM | 0.4 GPM | 0.26 GPM | 15-150 PSI (40 PSI Rec.) | 3 Showers | 3.5 (0.9) / 10.5 (2.6) | 8.0 (2) / 13.0 (3.2) | 3/4" NPT | 1/2" NPT | 100°F - 140°F (38°C-60°C) | Electronic Ignition | 120V, 50/60Hz, <5A | 50.3 dB | Sea Level to 10,100' (3,078.5 m) | -5°F (-21°C) | Up to 12 units | Power Direct Vent | 2", 75' (5cm, 22.9m); 3", 150' (8cm, 45.7m) | PVC, CPVC, Polypropylene | 33.8" (86 cm) | 16.5" (42 cm) | 16.1" (41 cm) | 104 lb (47 kg) | 15 years | 5 years |
| ADAPTTM+ Premium | ATHR-199X3 | Integrated | Integrated | Integrated | 10,000 - 199,000 | Natural Gas (Field Convertible to LP) | Single Stainless Steel | 0.95 | Ultra Low NOx | 10.5 GPM | 0.4 GPM | 0.26 GPM | 15-150 PSI (40 PSI Rec.) | 3 Showers | 3.5 (0.9) / 10.5 (2.6) | 8.0 (2) / 13.0 (3.2) | 3/4" NPT | 1/2" NPT | 100°F - 140°F (38°C-60°C) | Electronic Ignition | 120V, 50/60Hz, <5A | 50.3 dB | Sea Level to 10,100' (3,078.5 m) | -5°F (-21°C) | Up to 12 units | Power Direct Vent | 2", 75' (5cm, 22.9m); 3", 150' (8cm, 45.7m) | PVC, CPVC, Polypropylene | 41.8" (106 cm) | 16.5" (42 cm) | 16.1" (41 cm) | 104 lb (47 kg) | 15 years | 5 years |
| ADAPTTM SC Standard | ATM-160X3-N | Integrated | N/A | N/A | 10,000 - 160,000 | Natural Gas | Primary Copper, Secondary Stainless Steel | 0.95 | Ultra Low NOx | 10.5 GPM | 0.4 GPM | 0.26 GPM | 15-150 PSI (40 PSI Rec.) | 2.5 Showers | 4.0 (1.0) | N/A | 3/4" NPT | 3/4" NPT | 100°F - 140°F (38°C-60°C) | Electronic Ignition | 120V, 50/60Hz, <5A | 51 dB | Sea Level to 7,800' (2,377.4 m) | -5°F (-21°C) | Up to 12 units | Power Direct Vent | 2", 75' (5cm, 22.9m); 3", 150' (8cm, 45.7m) | PVC, CPVC, Polypropylene | 40.4" (102.6 cm) | 17.1" (43.5 cm) | 11.9" (30.1 cm) | 83 lb (37.7 kg) | 15 years | 5 years |
| ADAPTTM SC Standard | ATM-180X3-N | Integrated | N/A | N/A | 10,000 - 180,000 | Natural Gas | Primary Copper, Secondary Stainless Steel | 0.95 | Ultra Low NOx | 10.5 GPM | 0.4 GPM | 0.26 GPM | 15-150 PSI (40 PSI Rec.) | 3 Showers | 10.5 (2.6) | N/A | 3/4" NPT | 3/4" NPT | 100°F - 140°F (38°C-60°C) | Electronic Ignition | 120V, 50/60Hz, <5A | 51 dB | Sea Level to 7,800' (2,377.4 m) | -5°F (-21°C) | Up to 12 units | Power Direct Vent | 2", 75' (5cm, 22.9m); 3", 150' (8cm, 45.7m) | PVC, CPVC, Polypropylene | 40.4" (102.6 cm) | 17.1" (43.5 cm) | 11.9" (30.1 cm) | 83 lb (37.7 kg) | 15 years | 5 years |
| ADAPTTM SC Standard | ATM-199X3-N | Integrated | N/A | N/A | 10,000 - 199,000 | Natural Gas | Primary Copper, Secondary Stainless Steel | 0.95 | Ultra Low NOx | 10.5 GPM | 0.4 GPM | 0.26 GPM | 15-150 PSI (40 PSI Rec.) | 3 Showers | N/A | N/A | 3/4" NPT | 3/4" NPT | 100°F - 140°F (38°C-60°C) | Electronic Ignition | 120V, 50/60Hz, <5A | 51 dB | Sea Level to 7,800' (2,377.4 m) | -5°F (-21°C) | Up to 12 units | Power Direct Vent | 2", 75' (5cm, 22.9m); 3", 150' (8cm, 45.7m) | PVC, CPVC, Polypropylene | 40.4" (102.6 cm) | 17.1" (43.5 cm) | 11.9" (30.1 cm) | 83 lb (37.7 kg) | 15 years | 5 years |
