T-KJr2U - 140,000 BTU Natural Gas Outdoor Non-Condensing Ultra-Low NOx


T-KJr2U-OS-N (Outdoor)

The compact T-KJr2U is a fully modulating, gas fired, tankless water heater perfect for residential applications. With gas inputs of 140,000 BTU, the T-KJr2U can produce enough hot water for up to two bathrooms in warmer climates and it also complies with Ultra-Low NOx regulations of less than 14 ng/J (<20ppm)

Number of showers this unit can handle, depending on ground water temperature.

Warmer Climates

Cooler Climates


The T-KJr2U supplies hot water to domestic hot water systems (directly or indirectly) which can be used with storage tanks, recirculation systems, hydronic heating systems, radiant floor systems, and/or domestic & heating applications.

  • 15-year limited heat exchanger, 5 yrs limited parts Residential use
  • Energy Factor of 0.82 for Natural Gas
  • Maximum flow rate of 6.6 GPM at 35°F temperature rise (3.3 GPM at 70°F rise)
  • Includes a remote control as a standard feature
  • Safety features include freeze, overheat, surge protection, and troubleshooting diagnostic codes
  • Complies with Ultra-Low NOx regulations of less than 14 ng/J (<20ppm)

Tk 4 No -e

Tech Specs

Emissions: Ultra Low NOx
Maximum BTUs: 140,000
Minimum BTUs: 19,500
Water Connection Location: Bottom
Water Connection: 0.75"
Flow Rate: 6.60
Heat Exchanger: Copper
Voltage: AC 120V
Energy Factor: 0.82
ENERGY STAR® Qualified: No
LEED Rating:
Remote Control: Yes
Technology: Non-Condensing
Multilink: No

Dimensions & Venting

Height: 20.25"
Width: 13.75"
Depth: 9.50"
Product Weight: 37 lbs.
Vent Type: Direct Vent
Vent Size: 4"


This model is intended for Outdoor installation, no venting is required.

Please check the Product Manual for information on proper installation.


Recess Box

The 9007674005 Recess Box completely houses the tankless hot water unit and allows it to be completely recessed into a wall for a smooth, almost seamless look. It is just over 14 inches wide so it easily fits in-between the studs.

For Use with the following models:

T-KJr2-OS, T-KJr2U-OS, T-K4-OS, T-K4U-OS, T-D2-OS, T-D2U-OS

Pipe Cover

The 9007670005 Pipe Cover protects the plumbing pipes to the water heater from unexpected adjustments. This pipe cover is fixed to the bottom of the water heater, which hides the plumbing and improves the visual aspects of the whole installation for the water heater.

For Use with the following models:

T-KJr2U-IN, T-KJr2U-OS, T-K4-IN, T-K4-OS, T-K4U-IN, T-K4U-OS, T-D2-IN, T-D2-OS, T-D2U-IN, T-D2U-OS

Remote Temperature Controller

The 9008172005 Temperature Remote Controller (TM-RE40) is designed for commercial tankless applications that require higher outlet temperatures. It also works as a diagnostic tool that will give a concise error code whenever there is a problem with the unit.

For Use with the following models:

T-H3-IN, T-H3-OS

Lead Free Isolation Valves & Pressure Relief Valve

The 9007604005 Lead Free Isolation Valves & Pressure Relief Valves are used to isolate a unit for service. The Pressure Relief Valve is to help protect the unit and release if the pressure in the tankless water heater or hot water system exceeds 150 psi and up to 200,000 BTUs. For 3/4" water lines. (1953 Compliant)

For Use with the following models:

TK-110C-NI, TK-310C-NI, TK-510C-NI, T-KJr2/U, T-K4/U, T-D2/U, T-H3M, T-H3J, T-H3S, T-H3

Product Preservers® Anti-Scale System SM1.0L

The 9008877005 Product Preservers® Anti-Scale System provides protection from scale formation on internal and external plumbing surfaces. The Product Preservers® system is a single cartridge based system that must be installed on a cold water line prior to a single water-heating device (water heater or tankless water heater). Peak Flow Rate - 6 gpm (23 lpm)

For Use with the following models:

T-KJr2/U, T-K4/U, T-D2/U, T-H3M, T-H3J, T-H3S, T-H3-IN


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