Navien-app-icon-ci

Download the new Navien mobile app!

Apple iOSGoogle Android

Non-Condensing Tankless Water Heaters

A high-efficiency, space-saving technology that can supply endless domestic hot water for residential applications. Unlike bulky tank water heaters that continuously reheat water, wasting energy.

overhead view of woman holding glass of wine while relaxing in bubble bath

View All Navien
Non-Condensing Products

How Non-Condensing Tankless Water Heaters Work

High-efficiency non-condensing tankless units only heat water when you want it, unlike wasteful tank water heaters. In simple terms, cold water travels through one heat exchanger supplying endless hot water to the fixtures in your home. When you upgrade to a tankless water heater, you can save energy and money.

illustration of water flow inside non-condensing tankless water heater with components labeled
  1. When a hot water tap is opened, the tankless water heater detects the flow

  2. The flow sensor activates to determine the amount of hot water needed

  3. The igniter activates

  4. The gas control valve opens to supply the correct amount of gas

  5. The burner ignites providing a flame to heat the water

  6. Cold water passes through the heat exchanger

  7. The unit determines outgoing set temperature and adjusts the flame to heat the water

  8. Desired hot water amount delivered to the faucet

  1. When a hot water tap is opened, the tankless water heater detects the flow

  2. The flow sensor activates to determine the amount of hot water needed

  3. The igniter activates

  4. The gas control valve opens to supply the correct amount of gas

  5. The burner ignites providing a flame to heat the water

  6. Cold water passes through the heat exchanger

  7. The unit determines outgoing set temperature and adjusts the flame to heat the water

  8. Desired hot water amount delivered to the faucet

What is a non-condensing tankless water heater?

Non-condensing tankless water heaters are gas-fueled tankless water heaters with a single heat exchanger. Unlike condensing tankless water heaters, non-condensing models don’t have a secondary heat exchanger to capture and recycle heat from the exhaust gas.

 running shower head with the words non-condensing or condensing

What’s the difference between non-condensing & condensing tankless water heaters?

Non-condensing tankless water heaters have a heat exchanger (burner) that heats water as it flows through the unit. They vent hot exhaust gas which is why Navien non-condensing models are built with exhaust systems that tolerate high temperatures. Because the exhaust gas doesn't cool or condense inside the unit, non-condensing tankless water heaters don't need a drain.


Condensing tankless water heaters have a secondary heat exchanger that captures heat from the exhaust gas and uses it to preheat cold water before it’s fully heated by the primary heat exchanger. Because the exhaust gas loses heat and condenses inside the unit, condensing tankless water heaters require a drain and allow more types of venting material to be used.

Noncondensing-faucet

Are non-condensing tankless water heaters better than condensing? 

It depends on your preferences:


Non-condensing tankless water heaters offer more flexibility for installation because they don’t require a drain. They’re also smaller than condensing models, and need minimal maintenance. Non-condensing tankless water heaters have an efficiency rating of 0.81 UEF, which is much more efficient than traditional storage tank water heaters.


Condensing tankless water heaters offer an ultra-high efficiency rating of up to 0.96 UEF, as well as higher flow rates. They’re also compatible with more types of venting material like PVC and polypropylene. But condensing tankless water heaters need a drain for the condensate, and annual maintenance is recommended.

What type of venting is used for a non-condensing tankless unit? 

The exhaust temperature of a non-condensing tankless water heater is typically higher than that of a condensing tankless water heater.  Non-condensing tankless water heater typically require metal venting material in order to tolerate the higher temperature and corrosive nature of the exhaust gas. 

Condensing vs Non-Condensing Tankless Water Heaters

  Condensing Non-Condensing
Initial cost Usually higher than comparable non-condensing Usually lower than comparable condensing
Long term operating cost Lower than typical non-condensing tankless and storage tank system Could be higher than condensing but lower than storage tank systems
Efficiency Ultra-high Efficiency (UEF up to .96) High Efficiency (UEF > .80)
Maintenance requirement Annual service recommended Minimal
Venting PVC acceptable 3" x 5" metal concentric required
Installation Location Indoor or Outdoor Choice of interior or exterior
Durability Stainless steel heat exchanger extend service life Stainless steel heat exchanger extend service life
Dimensions Slightly larger than non-condensing, about 70-80% smaller than tank system Slightly smaller than condensing, 80% smaller than tank system

Navien Non-Condensing Tankless Water Heaters

 

The Navien NPN series is a line of indoor/outdoor non-condensing tankless water heaters. These tankless water heaters typically have a longer lifespan than condensing models and require less maintenance.

Navien NPN Premium Non-Condensing Tankless Water Heaters

Introducing The New NPN Series

NPN-U Series

Universal premium non-condensing tankless water heaters for indoor/outdoor installations.

NPN-160U
Max DHW Input: 160,000 BTU/h
Indoor or outdoor wall-hung
Residential/Commercial
Navien NPN-160U non-condensing tankless water heaters
View model
NPN-160U
NPN-180U
Max DHW Input: 180,000 BTU/h
Indoor or outdoor wall-hung
Residential/Commercial
Navien NPN-180U non-condensing tankless water heaters
View model
NPN-180U
NPN-199U
Max DHW Input: 199,900 BTU/h
Indoor or outdoor wall-hung
Residential/Commercial
Navien NPN-199U non-condensing tankless water heaters
View model
NPN-199U

NPN-E Series

Non-condensing tankless water heaters for outdoor installations.

NPN-160E
Max DHW Input: 160,000 BTU/h
Outdoor wall-hung
Residential/Commercial
Navien NPN-160E non-condensing tankless water heaters
View model
NPN-160E
NPN-180E
Max DHW Input: 180,000 BTU/h
Outdoor wall-hung
Residential/Commercial
Navien NPN-180E non-condensing tankless water heaters
View model
NPN-180E
NPN-199E
Max DHW Input: 199,900 BTU/h
Outdoor wall-hung
Residential/Commercial
Navien NPN-199E non-condensing tankless water heaters
View model
NPN-199E

Compare our advantages to other non-condensing tankless water heaters

Exclusive Navien NPN-Universal indoor or outdoor unit and NPN-Exterior dedicated outdoor unit. NPN-E outdoor models also feature remote control and built-in button controls for easy service. 

NPN-Universal indoor non-condensing tankless water heater, NPN-Universal non-condensing tankless water heater with optional vent cap for outdoor use, and NPN-Exterior non-condensing tankless water heater for outdoor use only
  • stainless steel heat exchanger for NPN non-condensing tankless water heaters

    Navitech™ exclusive stainless steel heat exchanger.

    NPN series are the first and only non condensing tankless water heaters with a stainless steel heat exchanger to deliver unmatched durability and performance.

  • Navitech stainless steel burner for non-condensing tankless water heaters

    Navitech™ stainless steel burner.

    Designed and manufactured by Navien to burn gas at higher efficiency than other systems on the market.

  • two NPN non-condensing tankless water heaters connected to operate as cascade system

    Cascading capability.

    For increased domestic hot water flow demand, the NPN can be cascaded with another NPN unit.

  • person at airport using NaviLink app to control tankless water heater over Wi-Fi

    NaviLink™ Wi-Fi remote control.

    This optional accessory enables you to control temperatures remotely, access usage data and receive diagnostic notifications on your smartphone or tablet.

  •  wall-mounted non-condensing tankless water heater 80% smaller than storage tank water heater

    Space saving and lighter weight design.

    These sleek wall-hung units use much less space and are substantially lighter than traditional tank water heaters and other non-condensing tankless water heaters.

  • woman and man on sofa watching TV with wall-mounted non-condensing tankless water heater nearby

    Low noise levels.

    Installations in or near media rooms, recreation rooms or any living areas of the house are possible with the quiet running NPN tankless water heaters.

Lower energy bills, easier on the planet

 
Unlike systems that waste energy to heat large tanks of water, Navien NPN series tankless units utilize 82¢ of every $1 to heat your water. NPN only fires up when hot water is needed, allowing great utility savings and a lower impact on the environment.

two young girls planting a tree in a field
mother and daughter wearing white robes in front of bubble bath

Find a Navien Tankless Water Heater Installer Near You

Find an Installer

Contact Us