Takagi Outdoor 8 GPM Natural or Takagi T-H3M Outdoor Natural Gas? Which Takagi Model to Buy
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Choosing between the takagi outdoor 8 gpm natural vs t h3m outdoor natural gas models requires looking at their core specifications. Both units are condensing, outdoor tankless water heaters powered by natural gas. They share the same fuel source and installation environment. The main difference lies in their physical dimensions and capacity ratings. One model offers a higher flow rate, while the other provides a more compact footprint. You need to decide which specification better matches your household’s hot water demands.
Key differences
| Aspect | Takagi Outdoor 8 GPM Natural Gas Water Heater | Takagi T-H3M Outdoor Natural Gas Heater |
|---|---|---|
| Flow Rate | 8 GPM | not listed |
| Dimensions | 24.9 x 17.8 x 11.3 inches | 29.5 x 13.1 x 17.8 inches |
| Weight | not listed | 44 pounds |
| Venting Type | Condensing | Condensing |
Which one should you choose?
Choose Takagi Outdoor 8 GPM Natural Gas Water Heater if
- You need a high flow rate of 8 gallons per minute for multiple simultaneous uses.
- You have limited vertical space but can accommodate a wider unit.
- You want a model explicitly rated for ultra-low NOx emissions.
Choose Takagi T-H3M Outdoor Natural Gas Heater if
- You have limited horizontal or width space available for installation.
- You prefer a unit with a known weight of 44 pounds for mounting planning.
- You are installing in an outdoor location and need a condensing natural gas heater.
Verdict: Choose the Takagi T-H3S-OS-N if your priority is an 8 GPM flow rate for high-demand households. Select the Takagi T-H3M if your installation space is constrained in width, as it is narrower. Both units deliver condensing efficiency for outdoor natural gas heating.
Takagi Outdoor Models Compared
Flow Rate Capacity
The Takagi Outdoor 8 GPM Natural Gas Water Heater lists a flow rate of 8 gallons per minute. This specification helps you understand how much hot water the unit can deliver simultaneously to multiple fixtures. The Takagi T-H3M Outdoor Natural Gas Heater does not list a flow rate in the provided data. Without this number, you cannot confirm if it matches the 8 GPM output. If you need a guaranteed high-volume supply for large households, the 8 GPM rating on the first model provides clear certainty. The second model leaves this critical performance metric undefined in the specs.
Physical Dimensions
Size matters for outdoor placement. The Takagi Outdoor 8 GPM unit measures 24.9 inches in height, 17.8 inches in width, and 11.3 inches in length. It has a more compact, boxy footprint. The Takagi T-H3M model is taller and narrower, standing 29.5 inches high with a width of 13.1 inches and a length of 17.8 inches. The T-H3M requires more vertical clearance but less horizontal space along a wall. You should measure your installation area carefully. The T-H3M fits tighter horizontally, while the 8 GPM model is shorter and wider.
Venting Technology
Both units utilize condensing venting technology. This means they extract heat from exhaust gases to improve efficiency before releasing them. Condensing models typically require PVC or CPVC venting pipes rather than traditional metal flues. Since both the Takagi Outdoor 8 GPM Natural Gas Water Heater and the Takagi T-H3M Outdoor Natural Gas Heater share this venting type, the installation requirements for exhaust are identical. You will need to plan for condensation drainage and appropriate plastic venting materials for either choice. There is no difference in this core efficiency feature between the two models.
Fuel Source
Both heaters run on natural gas. The specifications for the Takagi Outdoor 8 GPM Natural Gas Water Heater confirm natural gas fuel. The Takagi T-H3M Outdoor Natural Gas Heater also specifies natural gas as its fuel type. This means your existing gas line infrastructure can likely support either unit without conversion. You do not need to switch propane or electricity. The availability of natural gas is standard for outdoor installations in many regions. This shared characteristic simplifies the decision, as neither model requires a different energy source or specialized fuel storage.
Installation Location
Both units are designed for outdoor installation. The Takagi Outdoor 8 GPM Natural Gas Water Heater is listed for outdoor use. The Takagi T-H3M Outdoor Natural Gas Heater is also specified for outdoor installation. This allows you to place them on patios, decks, or exterior walls to save indoor space. You must ensure the location is protected from extreme weather or follows local codes for outdoor appliances. Since both share this trait, your site preparation needs remain the same regardless of which model you select. Neither unit is intended for indoor closets or garages.
Which Takagi Outdoor Model Fits You
Users needing high simultaneous flow
The Takagi T-H3S-OS-N delivers 8 GPM. This flow rate supports multiple fixtures running at once. If you need strong hot water output for showers and sinks, this model meets that demand. Its capacity ensures consistent performance during peak usage times.
Those with narrow installation spaces
The Takagi T-H3M-OS-N has a width of 13.1 inches. This is narrower than the 17.8-inch width of the T-H3S-OS-N. If your outdoor wall space is limited, the T-H3M fits better. Its compact width simplifies placement in tight areas.
Buyers prioritizing compact footprint
The Takagi T-H3S-OS-N measures 11.3 inches in length. This is shorter than the 17.8-inch length of the T-H3M-OS-N. If you want a unit that takes up less horizontal space, the T-H3S-OS-N is the better choice for your installation.
The products compared
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
The Takagi T-H3S-OS-N delivers 8 GPM of endless hot water using natural gas. This condensing outdoor unit meets 2012 SCAQMD Rule 1146.2 for ultra-low NOx emissions. Its compact design measures 24.9 by 17.8 by 11.3 inches. You get computerized safety features without a pilot light. It suits homes needing high flow rates in outdoor settings.
Pros
- 8 GPM flow rate for high demand
- Condensing technology for high efficiency
- Ultra-low NOx emissions compliance
- No pilot light required
- Compact outdoor installation size
Cons
- Requires outdoor installation only
- Natural gas fuel type limits flexibility
- Lacks digital display or remote control
Good fit if
- You need 8 GPM for multiple bathrooms
- You have an outdoor wall for mounting
- You want ultra-low NOx emissions
Skip if
- You need indoor installation
- You use propane fuel
- You require digital controls
Verdict: Takagi T-H3S Outdoor 8 GPM is a high-capacity outdoor heater for large households. It fits homes with strong natural gas lines and outdoor space.
Takagi T-H3M Outdoor Natural Gas Heater
Best for: outdoor natural gas condensing 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 is a condensing outdoor tankless water heater designed for natural gas. It features a compact white casing measuring 29.5 inches in height, 13.1 inches in width, and 17.8 inches in depth. Weighing 44 pounds, it fits well in tight exterior spaces. This unit suits homeowners needing reliable hot water delivery without the bulk of a traditional tank, leveraging condensing technology for efficiency in an outdoor setting.
Pros
- Condensing venting technology for efficiency
- Outdoor installation rated
- Compact dimensions of 29.5 x 13.1 x 17.8 inches
- Natural gas fuel type
Cons
- Heavier at 44 pounds compared to non-condensing counterparts
- Requires specific condensing venting setup
- Natural gas only, not propane compatible
Good fit if
- You need an outdoor unit for natural gas
- You want condensing efficiency in a small footprint
- You have space for a 29.5-inch tall unit
Skip if
- You require propane fuel compatibility
- You need an indoor-only installation
- You prefer a lighter unit under 40 pounds
Verdict: Takagi T-H3M Outdoor Natural Gas is a solid choice for outdoor natural gas installations needing condensing efficiency. It fits well where space is limited but venting complexity is manageable.
Specifications side by side
| Spec | Takagi Outdoor 8 GPM Natural Gas Water Heater | Takagi T-H3M Outdoor Natural Gas Heater |
|---|---|---|
| Fuel Type | Natural Gas | Natural Gas |
| Flow Rate | 8 GPM | not stated |
| Installation Location | Outdoor | Outdoor |
| Dimensions | 24.9 x 17.8 x 11.3 inches | 29.5 x 13.1 x 17.8 inches |
| Venting Type | Condensing | Condensing |
| Capacity | 8 Gallon | not stated |
| Weight | not stated | 44 pounds |
| Size | Medium | not stated |
| Color | White | White |
| Model | T-H3S-OS-N | TH3MOSNG |
Frequently asked questions
Which Takagi outdoor model is more compact for tight spaces?
The Takagi T-H3M Outdoor Natural Gas Heater is narrower. It measures 13.1 inches in width, while the 8 GPM model is 17.8 inches wide. The T-H3M is also taller at 29.5 inches compared to 24.9 inches. If your installation area has limited width, the T-H3M fits better. The 8 GPM unit is shorter but wider, requiring more horizontal clearance.
Does the 8 GPM model have a higher flow capacity?
Yes, the Takagi Outdoor 8 GPM Natural Gas Water Heater delivers 8 gallons per minute. The T-H3M model does not list a specific GPM rating in its published data. If you need to run multiple showers or faucets at once, the 8 GPM unit provides that higher volume. The T-H3M is designed for condensing efficiency rather than maximum flow.
Are both units condensing outdoor heaters?
Both the Takagi Outdoor 8 GPM model and the T-H3M are condensing heaters. They are both designed for outdoor installation only. Condensing technology captures heat from exhaust gases to improve efficiency. This means both units vent differently than non-condensing models. You must ensure your outdoor location allows for proper condensing venting requirements.
What is the weight difference between the two heaters?
The Takagi T-H3M Outdoor Natural Gas Heater weighs 44 pounds. The 8 GPM model does not list a weight in its specifications. The T-H3M is taller and narrower, while the 8 GPM unit is shorter and wider. Weight matters for mounting stability. You should verify your wall or bracket can support the 44-pound T-H3M.
Can I use these heaters with natural gas?
Yes, both models are designed for natural gas fuel. The Takagi Outdoor 8 GPM and the T-H3M both specify natural gas as their fuel type. They are not compatible with propane unless specifically converted by the manufacturer. Ensure your home has a natural gas line available at the installation site. Both units require proper gas pressure and line sizing for safe operation.
Which model is better for large households?
The Takagi Outdoor 8 GPM Natural Gas Water Heater is better for large households. It provides an 8 GPM flow rate, which supports multiple fixtures running simultaneously. The T-H3M model focuses on condensing efficiency in a smaller footprint. If your household has high hot water demand, the 8 GPM capacity meets that need more effectively.