Best Takagi Tankless Water Heaters: 5 Models Compared
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This guide compares the best takagi tankless water heaters available today. We analyzed 5 models based strictly on their published specifications. Takagi offers compact outdoor and indoor units in natural gas and propane options. These units feature condensing venting and vary in physical dimensions. The Takagi Outdoor 8 GPM Natural Gas Water Heater leads as the best overall choice for high-flow outdoor natural gas needs. Its medium size and efficient design make it a practical fit for many homes. All picks reflect the data provided in the product listings.
Quick picks
| # | Product | Best for | Price |
|---|---|---|---|
| 1 | Takagi Outdoor 8 GPM Natural Gas Water Heater Best overall | High-flow outdoor natural gas needs | Check price of Takagi Outdoor 8 GPM Natural Gas Water Heater on Amazon |
| 2 | Takagi T-H3M Outdoor Natural Gas Heater Best budget | outdoor natural gas efficiency | Check price of Takagi T-H3M Outdoor Natural Gas Heater on Amazon |
| 3 | Takagi Outdoor Propane Tankless Water Heater Also great | outdoor propane homes needing 8 GPM | Check price of Takagi Outdoor Propane Tankless Water Heater on Amazon |
| 4 | Takagi 6.6 GPM Propane Outdoor Heater Best premium | outdoor propane installations with emission rules | Check price of Takagi 6.6 GPM Propane Outdoor Heater on Amazon |
| 5 | Takagi 10 GPM Condensing Natural Gas Water Heater Best indoor | indoor homes needing 10 GPM natural gas | Check price of Takagi 10 GPM Condensing Natural Gas Water Heater on Amazon |
Our 5 picks
Takagi Outdoor 8 GPM Natural Gas Water Heater
Best for: High-flow outdoor natural gas needs
- Fuel Type
- Natural Gas
- Flow Rate
- 8 GPM
- Installation Location
- Outdoor
- Dimensions
- 24.9 x 17.8 x 11.3 inches
- Venting Type
- Condensing
- Capacity
- 8 Gallon
View on Amazon: Takagi Outdoor 8 GPM Natural Gas Water Heater Affiliate link
This Takagi T-H3S-OS-N is a condensing outdoor tankless water heater powered by natural gas. It delivers 8 gallons per minute, making it suitable for homes needing reliable hot water flow. The unit measures 24.9 by 17.8 by 11.3 inches and features computerized safety controls. It satisfies ultra-low NOx emission standards, offering energy conservation without a pilot light.
Pros
- 8 GPM flow rate for strong hot water output
- Condensing design for high energy efficiency
- Ultra-low NOx emissions compliant
- Computerized safety features with no pilot light
Cons
- Outdoor installation only
- Requires natural gas connection
- Larger footprint than compact indoor models
Good fit if
- You need high flow rates for multiple bathrooms
- You have an outdoor space for installation
- You want ultra-low emissions compliance
Skip if
- You require indoor installation
- You use propane fuel
- You need a compact unit for tight spaces
Verdict: Takagi 8 GPM Outdoor Natural Gas Heater provides strong flow and efficiency for outdoor use. It fits homes with natural gas lines and space for a medium-sized outdoor unit.
Takagi T-H3M Outdoor Natural Gas Heater
Best for: outdoor natural gas efficiency
- Fuel Type
- Natural Gas
- Installation Location
- Outdoor
- Dimensions
- 29.5 x 13.1 x 17.8 inches
- Venting Type
- Condensing
- Weight
- 44 pounds
View on Amazon: Takagi T-H3M Outdoor Natural Gas Heater Affiliate link
The Takagi T-H3M-OS-N is a condensing outdoor tankless water heater designed for natural gas. It weighs 44 pounds and measures 29.5 x 13.1 x 17.8 inches. This compact unit delivers reliable hot water without taking up much space. It suits homeowners with outdoor installation needs who want high efficiency. The white finish blends into most exterior settings. It is a solid option for single-family homes.
Pros
- Condensing technology for high efficiency
- Compact dimensions: 29.5 x 13.1 x 17.8 inches
- Lightweight at 44 pounds
- Designed specifically for outdoor installation
Cons
- Natural gas only; not compatible with propane
- Outdoor installation only; not for indoor use
- No smart home integration mentioned in specifications
Good fit if
- You need a high-efficiency unit for an outdoor location
- You have natural gas available at the installation site
- You prefer a compact and lightweight design
Skip if
- You require propane fuel compatibility
- You plan to install the unit indoors
- You need smart remote control features
Verdict: Takagi T-H3M Outdoor Natural Gas Heater is a practical, space-saving choice for outdoor natural gas setups. It fits well if you prioritize efficiency and compact size over smart features.
Takagi Outdoor Propane Tankless Water Heater
Best for: outdoor propane homes needing 8 GPM
- Fuel Type
- Propane
- Flow Rate
- 8 GPM
- Installation Location
- Outdoor
- Dimensions
- 24.9 x 17.8 x 11.3 in
- Venting Type
- Condensing
- Capacity
- 8 Gallon
View on Amazon: Takagi Outdoor Propane Tankless Water Heater Affiliate link
This Takagi unit delivers 8 gallons per minute of hot water using propane fuel. It is designed for outdoor installation and features condensing technology for high efficiency. The compact dimensions fit tight spaces, and it meets ultra-low NOx emission standards. You get endless hot water without a pilot light, making it suitable for homes needing reliable outdoor propane heating.
Pros
- 8 GPM flow rate
- Condensing high efficiency
- Ultra-low NOx emissions
- No pilot light required
Cons
- Propane fuel only
- Outdoor installation only
- 69 pounds weight
Good fit if
- You need 8 GPM capacity
- You use propane fuel
- You require outdoor placement
Skip if
- You need natural gas
- You require indoor installation
- You need higher flow rate
Verdict: Takagi 8 GPM Propane Outdoor Unit provides high efficiency and low emissions for outdoor propane setups. It fits buyers who need reliable hot water flow in compact outdoor spaces.
Takagi 6.6 GPM Propane Outdoor Heater
Best for: outdoor propane installations with emission rules
- Fuel Type
- Propane
- Flow Rate
- 6.6 GPM
- Installation Location
- Outdoor
- Dimensions
- 24.9 x 17.8 x 11.3 in
- Venting Type
- Condensing
- Capacity
- 4.0 Gallons
View on Amazon: Takagi 6.6 GPM Propane Outdoor Heater Affiliate link
This Takagi unit delivers 6.6 gallons per minute of hot water using propane fuel. It features a condensing design for high efficiency and ultra-low NOx emissions. The compact white casing measures 24.9 by 17.8 by 11.3 inches and weighs 52 pounds. You should choose this model if you need a reliable outdoor tankless water heater for your home.
Pros
- 6.6 GPM flow rate for steady hot water
- Condensing technology ensures high energy efficiency
- Meets strict SCAQMD Rule 1146.2 emission standards
- Compact outdoor design saves space
Cons
- Limited to propane fuel type only
- Outdoor installation only
- 4.0 gallon internal capacity is small
Good fit if
- You need a high-efficiency outdoor unit
- You have a propane gas supply
- You require ultra-low emission compliance
Skip if
- You need indoor installation capability
- You require natural gas compatibility
- You need a higher flow rate
Verdict: Takagi T-H3J Outdoor Propane Heater is a compact, high-efficiency solution for outdoor propane setups. It fits homeowners who need strict emission compliance and steady hot water flow in a small footprint.
Takagi 10 GPM Condensing Natural Gas Water Heater
Best for: indoor homes needing 10 GPM natural gas
- Fuel Type
- Natural Gas
- Flow Rate
- 10 GPM
- BTU
- 199,000 BTU/hr
- Installation Location
- Indoor
- Dimensions
- 22.5 x 17.8 x 10.8 in
- Venting Type
- Condensing
View on Amazon: Takagi 10 GPM Condensing Natural Gas Water Heater Affiliate link
This Takagi T-H3-DV-N is a natural gas tankless water heater designed for indoor installation. It delivers 10 gallons per minute using 199,000 BTUs. The condensing design meets ultra-low NOx emission standards. Its compact footprint measures 22.5 by 17.8 inches. You get reliable hot water on demand with integrated safety features. This unit suits homes needing steady flow in a confined space.
Pros
- 10 GPM flow rate for multiple fixtures
- 199,000 BTU/hr heating capacity
- Condensing technology for high efficiency
- Ultra-low NOx emissions compliance
- Commercial-grade copper alloy heat exchanger
Cons
- Heavier at 59 pounds
- Requires natural gas connection
- Indoor installation only
Good fit if
- You need 10 GPM for indoor use
- You want ultra-low NOx emissions
- You have natural gas available
Skip if
- You need outdoor installation
- You use propane fuel
- You require higher than 10 GPM
Verdict: Takagi T-H3-DV-N Indoor 10 GPM delivers steady hot water for indoor households with natural gas. It fits well in tight spaces where high efficiency and low emissions matter.
Specifications side by side
| Spec | Takagi Outdoor 8 GPM Natural Gas Water Heater | Takagi T-H3M Outdoor Natural Gas Heater | Takagi Outdoor Propane Tankless Water Heater | Takagi 6.6 GPM Propane Outdoor Heater | Takagi 10 GPM Condensing Natural Gas Water Heater |
|---|---|---|---|---|---|
| Fuel Type | Natural Gas | Natural Gas | Propane | Propane | Natural Gas |
| Flow Rate | 8 GPM | not stated | 8 GPM | 6.6 GPM | 10 GPM |
| BTU | not stated | not stated | not stated | not stated | 199,000 BTU/hr |
| Installation Location | Outdoor | Outdoor | Outdoor | Outdoor | Indoor |
| Dimensions | 24.9 x 17.8 x 11.3 inches | 29.5 x 13.1 x 17.8 inches | 24.9 x 17.8 x 11.3 in | 24.9 x 17.8 x 11.3 in | 22.5 x 17.8 x 10.8 in |
| Venting Type | Condensing | Condensing | Condensing | Condensing | Condensing |
| Capacity | 8 Gallon | not stated | 8 Gallon | 4.0 Gallons | not stated |
| Weight | not stated | 44 pounds | 69 pounds | 52 pounds | 59 pounds |
| Size | Medium | not stated | Medium | Medium | Medium |
| Color | White | White | No Finish | White | White |
| Model | T-H3S-OS-N | TH3MOSNG | T-H3S-OS-P | T-H3J-OS-P | T-H3-DV-N |
Takagi Tankless Heater Lineup Overview
You can choose between outdoor and indoor models based on your installation space. The outdoor units, like the Takagi Outdoor 8 GPM Natural Gas Water Heater and the Takagi T-H3M Outdoor Natural Gas Heater, are designed for exterior mounting. These units share condensing venting and natural gas fuel types, making them suitable for homes with existing gas lines and outdoor clearance. The propane outdoor options offer similar efficiency for different fuel sources.
For indoor needs, the Takagi 10 GPM Condensing Natural Gas Water Heater provides high flow in a compact footprint. It fits well in tight utility spaces where low emissions are important. All listed units feature condensing technology for efficiency. You should match your choice to your fuel source and whether you require outdoor or indoor installation. The capacity and physical dimensions vary slightly, so verify your space constraints before deciding.
Where Takagi Fits Your Needs
Takagi’s lineup focuses on compact, condensing units for outdoor and indoor use. You can choose between natural gas or propane fuel sources. The outdoor models range from the smaller T-H3M to the 8 GPM T-H3S-OS-N. Indoor options like the T-H3-DV-N offer higher flow rates. All listed units share a similar medium footprint, with widths around 17.8 inches. You will not find ventless, electric, or large whole-house storage heaters in this selection. If you need non-condensing technology or indoor propane units, this specific range does not cover those needs. The brand specializes in efficient, space-saving gas solutions.
How to Choose the Right Takagi Model
-
Check Fuel Source Availability
Match the heater to your home’s existing fuel lines. Takagi offers both natural gas and propane models. The T-H3S-OS-N runs on natural gas, while the T-H3S-OS-P uses propane. Selecting the wrong fuel type requires costly line modifications. Verify your current supply before purchasing. Both fuels support condensing technology for efficiency. Ensure your gas line diameter meets the unit’s requirements. This simple check prevents installation delays and ensures safe operation.
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Plan for Outdoor Space
Most Takagi models are designed for outdoor mounting. The T-H3M Outdoor Natural Gas Heater fits exterior walls efficiently. Its compact dimensions save space compared to larger units. Indoor models like the T-H3-DV-N require specific venting and clearance. If you lack outdoor space, consider indoor options. Outdoor units withstand weather but need proper drainage. Check local codes for mounting height and clearance. Proper placement ensures longevity and easy access for maintenance tasks.
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Match Flow Rate to Needs
Flow rate determines how many fixtures run simultaneously. The T-H3S-OS-N provides 8 gallons per minute. This suits homes with moderate simultaneous usage. The T-H3-DV-N offers 10 gallons per minute for higher demand. Lower flow units may struggle with multiple showers. Calculate your peak usage based on bathroom count. Higher flow rates require adequate gas pressure. Ensure your supply meets the unit’s BTU needs. Proper sizing prevents temperature drops during high usage periods.
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Understand Condensing Venting
All listed Takagi models use condensing venting technology. This method extracts more heat from exhaust gases. It improves efficiency and reduces energy costs. Condensing units produce acidic condensate that must drain. Install a proper drain line near the unit. Vent pipes can be smaller than traditional models. Check local codes for vent material requirements. PVC or CPVC pipes are often acceptable. Proper venting ensures safe operation and optimal performance. Neglecting this spec can lead to corrosion issues.
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Verify Physical Dimensions
Measure your installation space before buying. The T-H3M Outdoor Natural Gas Heater is 13.1 inches wide. The T-H3S-OS-N is 17.8 inches wide. Height and depth also matter for clearance. The T-H3-DV-N is 22.5 inches tall. Ensure you have room for service access. Tight spaces may require careful planning. Check weight limits for mounting surfaces. The T-H3S-OS-P weighs 69 pounds. Secure mounting prevents vibration and noise issues.
Frequently asked questions
Which Takagi model is best for outdoor use?
The Takagi Outdoor 8 GPM Natural Gas Water Heater is the top outdoor pick. It provides strong flow for high-demand applications. The unit features condensing venting for efficiency. Its medium size fits most exterior wall spaces. This model is ideal for homes with natural gas lines.
What is the smallest Takagi outdoor heater?
The Takagi T-H3M Outdoor Natural Gas Heater is a compact choice. It measures 13.1 inches in width and 29.5 inches in height. Weighing 44 pounds, it is easy to mount. This model prioritizes space-saving design and efficiency over smart features. It is a practical option for smaller outdoor setups.
Does Takagi make indoor tankless water heaters?
Yes, the Takagi 10 GPM Condensing Natural Gas Water Heater is designed for indoor use. It delivers steady hot water for households with natural gas. The unit measures 17.8 inches wide and 22.5 inches high. It fits well in tight indoor spaces while maintaining high efficiency and low emissions.
Which Takagi heater runs on propane?
Two models run on propane: the Takagi Outdoor Propane Tankless Water Heater and the Takagi 6.6 GPM Propane Outdoor Heater. The 8 GPM model weighs 69 pounds and offers high efficiency. The 6.6 GPM model weighs 52 pounds and ensures strict emission compliance. Both are built for outdoor propane setups.
How wide are Takagi outdoor units?
Most Takagi outdoor units share a width of 17.8 inches. This includes the 8 GPM Natural Gas, 8 GPM Propane, and 6.6 GPM Propane models. The T-H3M Outdoor Natural Gas Heater is narrower at 13.1 inches wide. Check these dimensions to ensure the unit fits your available wall space.
What venting type do Takagi heaters use?
All listed Takagi models use condensing venting. This technology improves efficiency and reduces emissions. It allows the units to operate effectively in both outdoor and indoor environments. Condensing venting is a key feature across the entire lineup, from the compact T-H3M to the high-capacity indoor T-H3-DV-N.
Which model has the highest flow rate?
The Takagi 10 GPM Condensing Natural Gas Water Heater has the highest flow rate. It is designed for indoor homes needing significant hot water. The outdoor 8 GPM models also provide strong flow. The 6.6 GPM Propane model offers a slightly lower output. Choose based on your household’s simultaneous hot water needs.