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NHW-199SE premium features and benefits
Exclusive NaviTech™ stainless steel heat exchanger. The NHW-S series is the first non condensing tankless water heater with a stainless steel heat exchanger to deliver unmatched durability and performance.
NPN - Exterior control panel allows you to adjust water temperature, operation status and troubleshooting.
Built-in Air Pressure Sensor (APS) monitors the vent system for blockage, automatically compensates for the range of vent lengths, helps maintain proper air/gas ratio during operation, and ensures consistent Domestic Hot Water output during changing conditions.
Patented NaviTech™ stainless steel burner. Designed and manufactured by Navien to burn gas at higher efficiency than other system on the market.
Recirculation control built into circuit board. Ensures proper system setup, and reduces the need for additional components, saving installation time and cost.
Built-in Water Adjustment Valve (WAV) and Mixing Valve control flow to maintain setpoint, and stabilize water temperature during flow changes.
NHW-199SE QuickFacts
14.0" W x 23.0" H x 9.3" D (35.6cm W x 58.4cm H x 23.6cm D)
Product approvals
- CSA
- Yes
- NSF(Standard 5)
- Yes
- Low Lead(<0.25%)
- Yes
- Ultra low NOx
- Yes
- AHRI Number
- 204524351 (Natural gas)
204524352 (Propane)
Efficiency Ratings*
- Uniform Energy Factor(UEF)
- 0.81
- MAX GPM(67°F Rise)
- 5.1 GPM (19.3 l/m)
*Based on U.S. Department of Energy (DOE) test procedures.**Based on a national average natural gas cost of $1.09/therm, propane cost of $2.41/gallon.
| Temp Rise | NHW-199SE |
|---|---|
| 30 °F (16.7 °C) rate | 11.1 GPM (42 l/m) |
| 35 °F (19.4 °C) rate | 9.5 GPM (36 l/m) |
| 40 °F (22.2 °C) rate | 8.3 GPM (31.4 l/m) |
| 45 °F (25 °C) rate | 7.4 GPM (28 l/m) |
| 50 °F (27.8 °C) rate | 6.6 GPM (25 l/m) |
| 55 °F (30.6 °C) rate | 6 GPM (22.7 l/m) |
| 60 °F (33.3 °C) rate | 5.5 GPM (20.8 l/m) |
| 65 °F (36.1 °C) rate | 5.1 GPM (19.3 l/m) |
| 70 °F (38.9 °C) rate | 4.7 GPM (17.8 l/m) |
| 75 °F (41.7 °C) rate | 4.4 GPM (16.7 l/m) |
| 80 °F (44.4 °C) rate | 4.1 GPM (15.5 l/m) |
| 85 °F (47.2 °C) rate | 3.9 GPM (14.8 l/m) |
| 90 °F (50 °C) rate | 3.7 GPM (14 l/m) |
| 100 °F (55.6 °C) rate | 3.3 GPM (12.5 l/m) |
| Model | NHW-199SE |
|---|---|
| DHW | 10,700 - 199,900 BTU/h (3.135 - 58.571 kWh) |
| Item | NHW-199SE | |
|---|---|---|
| Heat Capacity (input) | Domestic hot water | 10,700 - 199,900 BTU/h (3.135 - 58.571 kWh) |
| Efficiency ratings | Efficiency rating for NG & LP (UEF) | 0.81 |
| Flow rate (DHW) | 35°F temp rise | 9.5 GPM (36 l/m) |
| 45°F temp rise | 7.4 GPM (28 l/m) | |
| 67°F temp rise | 5.1 GPM (19.3 l/m) | |
| Dimensions | 14.0" W x 23.0" H x 9.3" D (35.6cm W x 58.4cm H x 23.6cm D) | |
| Weight | 65 lbs (29.5 kg) | |
| Installation location | Outdoor wall-hung | |
| Venting type | N/A | |
| Ignition | Electronic ignition | |
| DHW water pressure | 15-150 PSI (1.055-10.545 kg/cm2) | |
| Natural gas supply pressure (from source) | 3.5 " WC to 10.5 " WC (0.87 kPa to 2.61 kPa) | |
| Propane gas supply pressure (from source) | 8 " WC to 13 " WC (1.99 kPa to 3.23 kPa) | |
| Natural gas manifold pressure (min-max) | 3.2 " WC to 0.8 " WC (0.8 kPa to 0.2 kPa) | |
| Propane gas manifold pressure (min-max) | 6 " WC to 1.3 " WC (1.5 kPa to 0.32 kPa) | |
| Minimum flow rate | 0.5 GPM (1.893 l/m) | |
| Connection sizes | Cold water inlet | 3/4 |
| Hot water outlet size | 3/4 | |
| Gas inlet | 3/4 | |
| Power supply | Main supply | 120V AC, 60 Hz |
| Normal | 96 W | |
| Standby | 4 W | |
| Anti-frost | 114 W | |
| External pump | < 150 W, 1.5 A W | |
| Fuse | 5.0 A | |
| Materials | Casing | Cold rolled carbon steel |
| Heat exchangers | Stainless steel | |
| Safety Devices | Flame rod, APS, vent installation detector, ignition operation detector, water temperature high limit switch, power surge fuse | |
Navien reserves the right to change specifications at any time without prior notice.
NHW‑SE Videos
NHW-199SE FAQs
How long do outdoor tankless water heaters last?
Outdoor tankless water heaters generally have a lifespan of about 15 to 20 years. Navien heat exchangers have a warranty of 15 years.
Does a tankless water heater need a dedicated gas line?
Navien tankless water heaters provide on-demand hot water. A gas line, sufficient combustion air, a vent to evacuate combustion gas, and an electrical outlet are required to operate the gas unit properly.
Do you have to vent an outdoor tankless water heater?
Using an outside tankless water heater frees up space indoors. No additional venting is required when installing an NHW-SE Series tankless water heater outside in non-freezing regions.
What are the requirements of an outdoor gas tankless water heater?
A gas tankless water heater installed outdoors will be exposed to the elements, so you should not install a tanklesswater heater outdoors if your region experiences freezing temperatures. Depending on the layout of your property and local building codes, there may be restrictions on where you can install an outdoor tankless water heater. It will need to be a certain distance away from windows, doors and ventilation intakes to prevent exhaust gas from entering the building.
How do you decide between an indoor or outdoor tankless water heater?
Choosing between an indoor or outdoor tankless water heater depends on your region's climate, the space you have available for installation, and local code requirements. Outdoor water heaters should not be installed if there will be freezing temperatures. But in milder regions, an outdoor water heater can be a good solution if an indoor unit would require extensive or complex venting.
How do you install an outdoor gas tankless water heater?
Installing an outdoor water heater should always be done by a certified Navien technician by a licensed plumber - you can find an installer here. When installing an outdoor tankless water heater it's important to choose a location that allows maintenance access, satisfies local codes and proper installation requirements. You'll also need to make sure the wall can support the weight of the unit, and allow for connections to gas, water and electrical supply.
Can an outdoor tankless water heater be installed in a garage?
No, you cannot install an outdoor unit in a garage. Outdoor units can only be installed outdoors.
Can a tankless hot water heater be installed in a crawl space?
In comparison with traditional water heaters, tankless water heaters can be up to 34% smaller. Navien units can also be installed in more places, including crawl spaces and attics, since they are so small- about the size of a small suitcase.