Product Search • Checkout • 


Purchasing Multiple Units? 
Call for Wholesale Prices and Freight Shipping
Have Sizing or other Questions? Our Tankless Water Heating Pros are Ready to Help:

T-H3S-DV-NG 180,000 BTU Condensing Indoor Gas Tankless Water Heater

T-H3S-DV-NG 180,000 BTU Condensing Indoor Gas Tankless Water Heater

T-H3S-DV-NG 180,000 BTU Condensing Indoor Gas Tankless Water Heater
Click to enlarge image(s)
T-H3S-DV-N or T-H3S-DV-NG (Indoor Natural Gas Instant and Endless Hot On Demand Tankless Water Heater)

The T-H3S-DV-NG indoor naturla gas tankless water heater offers high efficiency Ultra-Low NOx condensing technology allowing for the use of 3" PVC venting and has 0" clearance to combustibles. Utilizing commerical grade copper alloy for the heat exchanger tubing. Are certified up to 10,100 ft. altitude.

Also referred to as T-H3S-IN-N and T-H3S-IN-NG

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

Warmer Climates 

Cooler Climates 


The T-H3S-DV-NG 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.

The T-H3S-IN-NG instant and endless hot tankless water heater is a high efficient, condensing, tankless water heater perfect for residential 2 -3 bathroom applications. The T-H3S-DV-NG on demand natural gas indoor tankless water heater can produce enough hot water for three bathrooms in warmer climates or two baths in colder climates.
  • ENERGY STAR® qualified
  • For 2 - 3 Bathroom Home Homes
  • Primary heat exchanger utilizes commercial-grade copper alloy for 25 times better heat transfer than stainless steel
  • Secondary heat exchanger utilizes 316L stainless steel for better corrosion resistance
  • Complies with Ultra-Low NOx regulations of less than 14 ng/J (<20ppm)
  • Integrated controls and power cord as standard features
  • Venting with Schedule 40 PVC, CPVC, PP, Category III stainless steel
  • Safety features include freeze, overheat, surge protection, and troubleshooting diagnostic codes
  • 15-year limited heat exchanger, 5 yrs limited parts Residential use

Tech Specs

Emissions: Ultra Low NOx
Maximum BTUs: 180,000
Minimum BTUs: 19,500
Water Connection Location: Bottom
Water Connection: 3/4"
Flow Rate: 8.00
Heat Exchanger: Copper & Stainless
Voltage: AC 120V
UEF: 0.95
ENERGY STAR® Qualified: Yes
LEED Rating: 1.5
Remote Control: No
Technology: Condensing
Multilink: No

Dimensions & Venting

Height: 22.50"
Width: 17.75"
Depth: 10.75"
Product Weight: 71 lbs.
Vent Type: Direct Vent
Vent Size: 4"