11 Best Outdoor Tankless Water Heater Natural Gas of 2026 With Freeze Protection

1

Rheem RTG-84XLN-3 High Efficiency Non-Condensing Outdoor Tankless Natural Gas Water

View on Amazon

• BWP Score

  BWP Score is a ranking system developed by Bestwinterproducts.com. BWP score has no relationship or impact from any manufacturers or sales agent websites. Learn more

  9.7
• Brand
  Rheem

Key specs2

Heating Capacity

180,000 BTU at 8.4 GPM max flow

Warranty Coverage

Includes 15-year heat exchanger protection and 5-year parts coverage when installed by a qualified technician.

Pros & cons42

Pros

• Delivers 8.4 GPM at a 35-degree rise to supply 3 to 4 simultaneous showers from a 180,000 BTU burner
• Features a 15-year warranty on the heat exchanger alongside 5-year parts coverage
• Non-condensing design achieves a 0.82 UEF rating without requiring indoor exhaust venting
• Integrated freeze protection and flame failure monitoring safeguard outdoor operation

Cons

• Lacks built-in WiFi connectivity for mobile app adjustments
• Manufacturer requires professional installation to validate warranty terms

2

Rheem RTG-70XLN-3 High Efficiency Non-Condensing Outdoor Tankless Natural Gas Water

View on Amazon

• BWP Score

  BWP Score is a ranking system developed by Bestwinterproducts.com. BWP score has no relationship or impact from any manufacturers or sales agent websites. Learn more

  9.3
• Brand
  Rheem

Key specs2

Simultaneous Shower Output

Supports 2 to 3 showers at once

Efficiency Rating

Maintains a 0.82 Uniform Energy Factor for on-demand outdoor natural gas heating without indoor flues.

Pros & cons42

Pros

• Produces 160,000 BTU and 7.0 GPM at 35-degree rise for 2 to 3 simultaneous showers
• Non-condensing outdoor build delivers a 0.82 UEF rating with zero indoor venting
• Built-in freeze protection and digital LED panel with 1-degree precision
• Long-term coverage with a 15-year heat exchanger and 5-year parts warranty

Cons

• Lower 7.0 GPM flow rate may throttle high-demand households with 4 or more fixtures
• No remote control or wireless app support included in the package

3

Natural Gas Tankless Water Heater,5.26GPM 20L Outdoor,Instant Hot Natural Gas

View on Amazon

• BWP Score

  BWP Score is a ranking system developed by Bestwinterproducts.com. BWP score has no relationship or impact from any manufacturers or sales agent websites. Learn more

  9.3
• Brand
  VELPAX

Key specs2

Indoor Temperature Remote

A dedicated indoor control panel lets you adjust temperatures from 95°F to 149°F without walking outside.

Water Pressure Range

Operational from 3.6 to 150 PSI

Pros & cons42

Pros

• Includes an indoor remote control panel to set temperatures between 95°F and 149°F
• Activates reliably at low water pressures starting at 3.6 PSI
• Water servo and four-stage combustion keep temperature swings within 1 degree
• Stainless steel body and oxygen-free copper heat exchanger resist corrosion

Cons

• Limited to 120,000 BTU heating capacity during deep winter cold snaps
• Requires an exterior 120V AC electrical outlet within reach of the power cord

4

Natural Gas Tankless Water Heater, Outdoor Installation, Up to 5.3

View on Amazon

• BWP Score

  BWP Score is a ranking system developed by Bestwinterproducts.com. BWP score has no relationship or impact from any manufacturers or sales agent websites. Learn more

  9.1
• Brand
  LiberLive

Key specs2

Wind and Weather Resistance

Engineered with a DC fan and IPX4 housing certified to stay operational in winds up to force 8.

Combustion Management

Staged burner control within 1 degree

Pros & cons42

Pros

• DC blower fan and reinforced casing withstand up to force 8 outdoor winds
• IPX4 waterproof rating with built-in freeze and sun protection
• Bundled indoor remote controller eliminates outdoor adjustments in winter
• Staged combustion system regulates gas flow within 1 degree of target temperature

Cons

• Max 130,000 BTU burner may limit flow rate when incoming groundwater is freezing
• Listing does not specify inlet pipe connection sizes

5

Natural Gas Tankless Water Heater, Outdoor Installation, Up to 5.3

View on Amazon

• BWP Score

  BWP Score is a ranking system developed by Bestwinterproducts.com. BWP score has no relationship or impact from any manufacturers or sales agent websites. Learn more

  8.7
• Brand
  LiberLive

Key specs2

Casing and Finish

Finished in protective gray with corrosion-resistant exterior panels and stainless steel vents.

Outdoor Protection Level

IPX4 water-resistant and freeze-protected

Pros & cons42

Pros

• Weather-shielded gray exterior with IPX4 waterproofing and freeze protection
• High-powered DC fan maintains stable burner combustion in force 8 winds
• Digital remote controller allows temperature management from inside the home
• Delivers 130,000 BTU across up to 3 to 4 fixtures simultaneously

Cons

• Moderate 5.3 GPM top output requires staggering baths during peak winter mornings
• Specific plumbing port diameters are omitted from manufacturer documentation

6

Westinghouse Tankless Water Heater Natural Gas Outdoor, CSA Certified

View on Amazon

• BWP Score

  BWP Score is a ranking system developed by Bestwinterproducts.com. BWP score has no relationship or impact from any manufacturers or sales agent websites. Learn more

  8.2
• Brand
  Westinghouse

Key specs2

Plumbing Connection Size

Standard 3/4-inch NPT water and gas ports

Heat Exchanger Warranty

Backed by a 5-year warranty on the heat exchanger and 2-year coverage on the overall unit.

Pros & cons42

Pros

• High 180,000 BTU capacity supports up to 8.1 GPM across 3 to 5 simultaneous fixtures
• Standard 3/4-inch NPT plumbing fittings integrate directly with typical home gas lines
• Variable-speed combustion fan compensates for outdoor wind changes
• Integrated electric freeze protection prevents freezing damage in cold seasons

Cons

• Shorter 5-year heat exchanger warranty compared to premium competing brands
• Requires dedicated 120V AC electrical power to run the internal fan and controls

7

Ranein Natural Gas Tankless Water Heater, 8.5 GPM, 190,000 BTU,

View on Amazon

• BWP Score

  BWP Score is a ranking system developed by Bestwinterproducts.com. BWP score has no relationship or impact from any manufacturers or sales agent websites. Learn more

  8.0
• Brand
  Ranein

Key specs2

Blower Fan Placement

Bottom-mounted blower dynamically adjusts speed against exterior wind pressure to eliminate backflow.

High-Altitude Restriction

Not recommended above 2,000 feet altitude

Pros & cons42

Pros

• Robust 190,000 BTU heating capacity supplies up to 8.5 GPM for 4 to 6 outlets
• Bottom-mounted blower fan adjusts speed against wind pressure to stop smoke backflow
• Standard 3/4-inch NPT fittings for straightforward water and gas line connection
• Built-in freeze protection protects internal plumbing circuits from cracking

Cons

• Not recommended for home installations at altitudes above 2,000 feet
• Requires manual draining via pressure relief valve if left idle in freezing weather

8

Outdoor Natural Gas Tankless Water Heater, 190,000 BTU, 8.1 GPM

View on Amazon

• BWP Score

  BWP Score is a ranking system developed by Bestwinterproducts.com. BWP score has no relationship or impact from any manufacturers or sales agent websites. Learn more

  7.8
• Brand
  Konfino

Key specs2

Low-Flow Activation

Starts heating at 0.79 GPM water flow

Wired Indoor Controller

Enables precise one-degree temperature adjustments between 95°F and 149°F from inside the home.

Pros & cons42

Pros

• Delivers 190,000 BTU and 8.1 GPM to run up to 3 showers and 3 faucets simultaneously
• Low 0.79 GPM minimum activation flow supports low-flow faucets and weak pressure
• Wired indoor controller adjusts temperatures from 95°F to 149°F with 1-degree precision
• Wind resistance up to level 10 paired with electric freeze and flame-failure safety

Cons

• Running the controller cable indoors requires drilling an exterior wall access hole
• Demands a full 3/4-inch gas line to maintain full 190,000 BTU burner output

9

Outdoor Natural Gas Tankless Water Heater, 110000 BTU 4.76 GPM

View on Amazon

• BWP Score

  BWP Score is a ranking system developed by Bestwinterproducts.com. BWP score has no relationship or impact from any manufacturers or sales agent websites. Learn more

  7.6
• Brand
  VELPAX

Key specs2

Gas Line Fitting Size

Standard 1/2-inch NPT water and gas ports

Remote Cable Length

Includes an indoor digital remote control panel connected by a 16.4-foot extension cable.

Pros & cons42

Pros

• Features a 16.4-foot cable on the indoor remote panel for easy temperature changes
• Uses compact 1/2-inch NPT fittings compatible with standard smaller-diameter branch lines
• Low startup water pressure requirement of just 3 PSI for rural or gravity-fed setups
• Weather-resistant body withstands rain, wind, and freezing temperatures

Cons

• Lower 110,000 BTU output produces 4.76 GPM, limiting multi-bath simultaneous winter use
• Must be manually drained when unused during extreme sub-zero cold spells

10

CAMPLUX 150,000 BTU Tankless Water Heater Natural Gas Outdoor Up

View on Amazon

• BWP Score

  BWP Score is a ranking system developed by Bestwinterproducts.com. BWP score has no relationship or impact from any manufacturers or sales agent websites. Learn more

  7.6
• Brand
  CAMPLUX ENJOY OUTDOOR LIFE

Key specs2

Gas Burner Modulation

A three-stage automatic burner flame row adjusts heat input on demand to hold output within 1 degree.

Fixture Capacity

Supports 3 to 5 simultaneous water outlets

Pros & cons42

Pros

• Supplies 150,000 BTU and up to 6.4 GPM to support 3 to 5 domestic water fixtures
• Three-speed automatic flame row adjustment stabilizes water temperature within 1 degree
• Standard 3/4-inch NPT water and natural gas connections simplify installation
• CSA-certified multi-protection system includes freeze, dry-fire, and overheat safety

Cons

• Does not include an indoor remote control for remote temperature adjustments
• Delivers 5.28 GPM under standard conditions rather than the maximum theoretical 6.4 GPM

11

MIZUDO MIZUDO Natural Gas Tankless Water Heater Indoor&Outdoor Convertible Installation

View on Amazon

• BWP Score

  BWP Score is a ranking system developed by Bestwinterproducts.com. BWP score has no relationship or impact from any manufacturers or sales agent websites. Learn more

  7.2
• Brand
  MIZUDO

Key specs2

Smart App Monitoring

Integrated WiFi connects to a smartphone app for tracking energy usage and adjusting target heat remotely.

Outdoor Conversion Requirement

Requires separate outdoor kit purchase

Pros & cons42

Pros

• Built-in WiFi allows mobile app temperature control and energy usage monitoring
• Stainless steel combustion chamber and deoxidized copper core resist heavy corrosion
• Advanced flow sensors and gas modulation keep water temperatures within 1 degree
• CSA certified for whole-home use delivering up to 5.1 GPM

Cons

• Outdoor installation requires purchasing a separate outdoor conversion accessory kit
• Maximum 120,000 BTU capacity can limit simultaneous shower flow during freezing weather

Last update on 2026-10-22 / Affiliate links / Images, Product Titles, and Product Highlights from Amazon Product Advertising API

Can a high-output outdoor natural gas tankless water heater run three showers at once?

Yes, units with ratings of 190,000 BTU and flow rates around 8.1 GPM are specified to supply three showers plus three faucets running at the same time. These high-output heaters maintain steady hot water with minimum activation flows as low as 0.79 GPM. In contrast, models producing 160,000 BTU deliver 7.0 GPM at a 35°F temperature rise, which fits two to three simultaneous fixtures depending on incoming groundwater temperatures.

How does an outdoor natural gas tankless water heater prevent freezing in winter?

Outdoor units feature built-in electric anti-freeze protection systems alongside overheat and flame failure devices to protect heat exchangers from sudden cold snaps. These heaters require a continuous 110V electrical supply to power their internal heating elements and safety controls when outdoor temperatures drop. If your home has severe power interruptions or limited utility access, you can also review an electric tankless water heater for home installation to evaluate different fuel and service panel demands.

Do outdoor natural gas heaters require a 3/4-inch gas line or can they use a 1/2-inch line?

Gas line diameter requirements vary by model and total heat output. Check the manufacturer specifications and product manual to verify whether the inlet connection requires a 3/4-inch or 1/2-inch NPT pipe. Units delivering between 160,000 and 190,000 BTU pull significantly more fuel during peak demand than smaller 110,000 or 130,000 BTU heaters, so confirm your gas meter delivery pressure and line run distance with a qualified technician before hooking up.

Can you adjust the water temperature from inside the house?

Yes, many outdoor natural gas tankless models eliminate trips outside by offering indoor controls. Certain models include a wired indoor digital remote with a 16.4-foot connection cable that allows precise adjustment from 95°F to 149°F with one-degree accuracy. Other convertible outdoor models integrate Wi-Fi connectivity, allowing you to adjust temperature settings and monitor energy usage directly through a mobile phone application.

How do outdoor tankless units prevent burner blowouts during windy weather?

Outdoor gas heaters use enclosed, corrosion-resistant steel cabinets and specialized venting paired with high-power DC blowers to maintain stable combustion in heavy drafts. In several designs, blowers located underneath the unit automatically modulate their rotating speed to match ambient airflow, preventing smoke backflow and flame disruption. Combined with automated flame failure detection, these forced-air systems keep the burner lit safely without requiring indoor flue routing.

What household size fits a smaller 110,000 to 130,000 BTU outdoor tankless heater?

Heaters in the 110,000 to 130,000 BTU range deliver maximum flow rates between 4.76 and 5.3 GPM, which suits smaller households running one or two hot water outlets simultaneously. While higher-capacity 180,000 to 190,000 BTU heaters support busy whole-home demands, a lower-output unit easily satisfies targeted living areas or secondary additions. If you only need immediate hot water for a single isolated fixture rather than general household supply, you can review a water heater for isolated sinks to match dedicated fixtures.