Takagi TK-110U Indoor/Outdoor NG/LP UltraLow NOx Tankless Water Heater

Modulating, compact, wall-mounted tankless water heater with ultra-low pollution emissions

The TK-110U is perfect for apartments, summer cabins, condos, and one bath homes in cold climates. It can be used with recirculation systems, combined domestic & heating applications, and water storage tanks.

Ships ready for Natural Gas, with LP Propane Conversion Kit included.

Indoor models include an integrated temperature controller and attached power cord with plug.
Outdoor models include a remote control unit.

Takagi Ultra-Low NOx tankless water heater features

Freeze Protection

Every tankless heater by Takagi has an internal freeze protection system, rated to protect the heaters in sub-freezing conditions. This prevents water temperatures in the heat exchanger from falling below a certain level, to prevent freeze damage.

Hi-Limit Switch

This ensures that the water temperature does not exceed dangerous levels. It disengages the gas valves, which effectively shuts down the water heater.

Air-Fuel Ratio Sensor

Takagi's unique sensor monitors and maintains optimal combustion at all times. The onboard computer adjusts the fan motor speed to make sure that air and fuel are mixed in the proper ratio to minimize emissions and maximize efficiency.

HRS35 Copper Alloy

The HRS35 copper alloy is heat-resistant, with additive elements which make it much harder and stronger than the standard C1220 copper alloy commonly used in other heat exchangers. HRS35 is 8 times stronger than regular copper, even at high temperatures. It's also resistant to the damaging effects of corrosion which is the leading cause of leaks in heat exchangers.

Drum Thickness

At every ignition cycle, thermal expansion causes every heat exchanger to undergo heat stress. The thousands of ON/OFF cycles typical in commercial applications can be damaging to water heaters. This is why Takagi's commercial products utilize heat exchangers with drums that are 25% thicker to ensure durability. A thicker drum produces less strain for the heat exchanger.

Better Water Pathway Design

By redirecting and redesigning water flow, the heat exchanger drum and finned coil's temperature stay above dew point, making it more difficult for condensation to build up.

Fin Pitch

Widening the pitch at the heat exchanger fins not only improves durability by reducing blockage, but it also maintains higher temperature levels on the upper finned coils. Keeping an elevated temperature at these coils reduces the chances of condensation buildup.

Match the Unit to Your Needs

	Warmer Climates 70°F Incoming Groundwater Temperature		Colder Climates 50°F Incoming Groundwater Temperature
	Capacity - Number of Shower Heads
TK-110U	2		1
TK-310U	3		2
T-TH3J	2		1
T-H3S	3		2
T-H3	4		3
TK-510U	4		2
T-M32	4		3
T-M50 / TM50	6		4

Flow Rate Guide (values are in gallons per minute, "GPM")

Specifications

Certifications and compliances

≈ Complies with lead-free standards
≈ Complies with Ultra-Low NOx regulations (SCAQMD Rule 1146.2 and other air quality management districts with similar requirements for Ultra-Low NOx emissions requirements of 14 ng/J or 20 PPM.) Meets ASHRAE 90.1b-1992 energy efficiency requirements.

ANSI Z21.10.3 ・ CSA 4.3

Dimensions

Warranty

• Residential Use: 15 yrs limited heat exchanger, 5 yrs limited parts
• Commercial Use: 5 yrs limited heat exchanger, 5 yrs limited parts

Downloads

• Spec Sheet
• Installation/User's Manual
• NG to LP Gas Conversion Guide
• Product Guide

Alias model numbers for the TK-110U: TK110U, TK110UING, AT-KJr3U-IN, AT-KJr3U-OS

Frequently Asked Question ("FAQ")

Q1: What are the differences between the TK-110 and the TK-110U?
A1.1: The TK-110U adds a 3" flue opening for fresh air for combustion intake. The TK-110 took in fresh air from the grill at the bottom front of the heater.
1.2. The  TK-110U complies with Ultra Low-NOX standards. 
1.3. The water connections at the bottom of the heater are in different locations. The gas connection remains at the far right side.