Forimo Natural Gas Tankless Water Heater Alternatives: 6 Similar Picks Compared
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If you are looking for forimo natural gas tankless water heater alternatives, you likely need to compare specific performance metrics. The original Forimo 4.74 GPM model offers strong flow for indoor use with natural gas. It delivers up to 81,888 BTU per hour and includes a digital display for precise temperature control. These specs make it suitable for homes with multiple simultaneous water demands.
You might seek other options if you require a different flow rate, size, or venting method. The alternatives listed here were chosen because their published specifications overlap with the original unit. This list includes 6 similar picks that share core traits like indoor installation and natural gas fuel. Each entry is ranked by how well its specs match common household needs. You can compare flow rates, dimensions, and features to find the best fit for your space.
Our top pick: Forimo 4.74 GPM Natural Gas Tankless Water Heater.
Comparing Alternative Gas Heaters
Forimo 4.74 GPM Indoor Natural Gas Water Heater
This Forimo model shares the same 4.74 GPM flow rate and natural gas fuel type as the original. The primary difference is physical dimensions. It stands 22 inches tall with a 13.8-inch width, making it slightly taller than the original 21.7-inch unit. The depth remains identical at 13.8 inches. Both units feature digital displays and indoor installation capabilities. You should choose this alternative if your vertical space allows for the extra half-inch height. The performance metrics for water output and heating capacity remain consistent with the top pick, ensuring similar simultaneous fixture support.
Forimo 4.21 GPM Natural Gas Indoor Heater
This unit reduces the flow rate to 4.21 GPM compared to the original 4.74 GPM. It is designed for smaller households or those with lower simultaneous water demands. The physical footprint changes significantly, measuring 14.4 inches in width and depth, and 25.4 inches in height. This makes it taller and slightly wider than the original. It retains the natural gas fuel type and indoor installation requirement. The digital display feature is preserved. Select this model if you prioritize a different form factor or do not need the maximum flow rate. The lower GPM may be sufficient for kitchens or single-bathroom setups.
Forimo 4.21 GPM Natural Gas Tankless Water Heater
This alternative also offers a 4.21 GPM flow rate, which is lower than the original 4.74 GPM. Its most distinct feature is its compact vertical profile. It stands only 4.72 inches tall but extends 25.4 inches in length. This horizontal orientation differs from the original’s standard upright design. It weighs 23 pounds and uses natural gas for indoor use. The digital display is included. This shape may suit installations where vertical clearance is limited but horizontal space is available. The reduced flow rate means it is better suited for single-point use or smaller households compared to the higher-capacity original model.
Forimo 4.74 GPM 18L Indoor Natural Gas Tankless Heater
This Forimo model matches the original exactly in flow rate, delivering 4.74 GPM of hot water. It shares the same 18L size classification and natural gas fuel type. The dimensions are identical, measuring 21.7 inches in height and 13.8 inches in both width and depth. The weight is listed at 23.2 pounds. It includes a digital display and is intended for indoor installation. The main difference lies in the model number and minor internal component variations. You would pick this version if the original is unavailable. It provides the same performance profile and spatial requirements, making it a direct functional equivalent for high-flow indoor needs.
EZ Tankless Ultra HE Natural Gas Water Heater
The EZ Tankless Ultra HE uses condensing technology, which typically improves efficiency but often results in a lower flow rate than non-condensing units. It measures 27 inches in length and 14.5 inches in width, making it longer and wider than the original. The height is only 6.5 inches, offering a low-profile design. It is a natural gas unit for indoor use with a digital display. This model sacrifices peak flow speed for energy efficiency. Choose this alternative if you prioritize lower gas consumption and have the space for a wider unit. The larger footprint and different dimensions require checking venting and clearance requirements against the original's compact design.
Camplux 3.18 GPM Indoor Natural Gas Heater
This Camplux unit provides a 3.18 GPM flow rate, which is significantly lower than the original 4.74 GPM. It is designed for moderate household usage rather than high-demand scenarios. The dimensions are 22.8 inches in height and 14.3 inches in both width and depth. It uses natural gas for indoor installation and features a digital display. The smaller flow rate makes it suitable for homes with fewer simultaneous water points. Select this model if you value a slightly more compact footprint and do not need the maximum output of the Forimo original. The trade-off is reduced capacity for showers or appliances running at the same time.
Quick picks
Our 7 picks
Forimo 4.74 GPM Natural Gas Tankless Water Heater
Best for: Indoor natural gas homes needing high flow
- Fuel Type
- Natural Gas (LNG)
- Flow Rate
- 4.74 GPM
- BTU
- 81,888 BTU/hour
- Installation Location
- Indoor
- Temperature Control
- Fahrenheit digital display
- Dimensions
- 21.7 x 13.8 x 13.8 inches
View on Amazon: Forimo 4.74 GPM Natural Gas Tankless Water Heater Affiliate link
This Forimo unit delivers 4.74 GPM at 81,888 BTU for indoor natural gas lines. It features stainless steel construction, an oxygen-free copper heat exchanger, and an LED display for precise temperature control. The compact 21.7-inch height saves space while supporting simultaneous use in bathrooms and kitchens. It requires only 3.6 PSI water pressure and includes safety protections against overheating and flame failure.
Pros
- High flow rate of 4.74 GPM for multiple fixtures
- 81,888 BTU output handles simultaneous hot water demand
- Corrosion-resistant stainless steel and copper heat exchanger
- LED digital display allows easy temperature adjustment
- Low water pressure requirement of 3.6 PSI
Cons
- Indoor installation requires proper venting and smoke exhaust
- Higher flow rate may exceed needs for single faucet use
- Limited to natural gas; not compatible with propane
Good fit if
- You need high flow for simultaneous bathroom and kitchen use
- You have a standard indoor natural gas line
- You want precise temperature control via a digital display
Skip if
- You require outdoor installation without venting
- You use propane or liquid petroleum gas
- You need a unit for a single sink only
Verdict: Forimo 18L Natural Gas Water Heater offers strong performance for households needing reliable hot water for multiple fixtures. It is best for indoor homes with natural gas connections that prioritize flow rate and durability.
Forimo 4.74 GPM Indoor Natural Gas Water Heater
Best for: High-flow indoor natural gas needs
- Fuel Type
- Natural Gas
- Flow Rate
- 4.74 GPM
- BTU
- 123,000 BTU/hr
- Installation Location
- Indoor
- Temperature Control
- Fahrenheit digital display
- Dimensions
- 22 x 13.8 x 13.8 inches
View on Amazon: Forimo 4.74 GPM Indoor Natural Gas Water Heater Affiliate link
This Forimo unit delivers 4.74 GPM at 123,000 BTU/hr for indoor natural gas use. It features a stainless steel body, copper heat exchanger, and LED digital display for temperature control. The unit requires only 0.2 MPa water pressure and includes multiple safety protections. It is designed for simultaneous use in bathrooms and kitchens, saving space compared to traditional tank heaters.
Pros
- High 4.74 GPM flow rate for multiple fixtures
- 123,000 BTU/hr output for rapid heating
- LED digital display for precise temperature adjustment
- Built-in oxygen-free copper water tank for durability
Cons
- Indoor installation only
- Requires dedicated exhaust venting for combustion gases
- Minimum water pressure of 0.2 MPa (29 PSI)
Good fit if
- You need high flow for simultaneous bathroom and kitchen use
- You have adequate ventilation for indoor exhaust
- You prefer digital temperature control
Skip if
- You require outdoor installation
- Your water pressure is below 29 PSI
- You need propane fuel compatibility
Verdict: Forimo 18L Natural Gas Water Heater offers strong performance for homes needing high flow rates indoors. It suits buyers who prioritize digital control and simultaneous fixture use with proper venting.
Forimo 4.21 GPM Natural Gas Indoor Heater
Best for: indoor homes needing steady hot water
- Fuel Type
- Natural Gas
- Flow Rate
- 4.21 GPM
- BTU
- 68,000 BTU/hr
- Installation Location
- Indoor
- Temperature Control
- 86°F-167°F
- Dimensions
- 25.4 x 14.4 x 14.4 inches
View on Amazon: Forimo 4.21 GPM Natural Gas Indoor Heater Affiliate link
This Forimo unit delivers 4.21 GPM at 68,000 BTU for indoor natural gas use. It features a stainless steel body with an oxygen-free copper heat exchanger for durability. The LED display lets you set water temperature between 86°F and 167°F. It includes anti-freezing and overheat protection. This model suits homes needing steady hot water for two to three fixtures simultaneously.
Pros
- 4.21 GPM flow rate supports multiple outlets
- 68,000 BTU/hr heating power
- Digital display with 86°F to 167°F range
- Stainless steel and copper construction
Cons
- Lower flow rate than 4.74 GPM competitors
- Indoor installation only
- Requires 2.5-inch vent pipe
Good fit if
- You need reliable hot water for a bathroom and kitchen
- You prefer a digital temperature display
- You have space for indoor installation
Skip if
- You require propane fuel
- You need more than 4.21 GPM
- You want outdoor installation
Verdict: Forimo 4.21 GPM Natural Gas Indoor Heater offers solid performance for small to medium households. It fits users who prioritize digital controls and durable materials over maximum flow rate.
Forimo 4.21 GPM Natural Gas Tankless Water Heater
Best for: indoor multi-fixture natural gas heating
- Fuel Type
- Natural Gas
- Flow Rate
- 4.21 GPM
- BTU
- 68,000 BTU/hr
- Installation Location
- Indoor
- Temperature Control
- 86°F-167°F
- Dimensions
- 14.4"W x 4.72"H x 25.4"L
View on Amazon: Forimo 4.21 GPM Natural Gas Tankless Water Heater Affiliate link
This Forimo unit delivers 4.21 gallons per minute of hot water using natural gas. It features a 68,000 BTU/hr output and an LED digital display for temperature control between 86°F and 167°F. The stainless steel and copper construction supports indoor installation. It is designed for simultaneous use at two to three fixtures. This model suits homes needing reliable indoor heating without a storage tank.
Pros
- 4.21 GPM flow rate for multi-point use
- 68,000 BTU/hr maximum power output
- LED digital display for precise temperature adjustment
- Stainless steel and oxygen-free copper construction
Cons
- Indoor-only installation requires venting
- Heavier build at 23 pounds
- Requires standard 1/2 inch NPT fittings
Good fit if
- You need indoor natural gas heating
- You want digital temperature control
- You require simultaneous multi-fixture flow
Skip if
- You need outdoor installation
- You require propane fuel type
- You prefer condensing technology
Verdict: Forimo 4.21 GPM Natural Gas Heater provides steady hot water for indoor residential use. It fits buyers who prioritize digital control and durable materials over outdoor flexibility.
Forimo 4.74 GPM 18L Indoor Natural Gas Tankless Heater
Best for: High-flow indoor natural gas needs
- Fuel Type
- Natural Gas (LNG)
- Flow Rate
- 4.74 GPM
- BTU
- 81,888 BTU/hour
- Installation Location
- Indoor
- Temperature Control
- Fahrenheit digital display
- Dimensions
- 21.7 x 13.8 x 13.8 inches
View on Amazon: Forimo 4.74 GPM 18L Indoor Natural Gas Tankless Heater Affiliate link
This Forimo unit delivers 4.74 GPM of hot water using natural gas. It features an 81,888 BTU/hour output and an LED digital display for temperature control. The stainless steel and copper construction supports indoor installation. It requires only 3.6 PSI water pressure. This model suits homes needing steady heat for multiple fixtures without a large footprint.
Pros
- 4.74 GPM flow rate for simultaneous use
- 81,888 BTU/hour heating capacity
- LED digital temperature display
- Low 3.6 PSI water pressure requirement
- Stainless steel and copper construction
Cons
- Indoor installation only
- Requires specific natural gas connection
- Heavier build at 23.2 pounds
Good fit if
- You need high flow for multiple bathrooms
- You have low water pressure
- You want digital temperature control
Skip if
- You need outdoor installation
- You use propane only
- You require a compact footprint
Verdict: Forimo 18L Natural Gas Indoor Heater provides strong performance for busy households. It is a solid choice for indoor spaces where high flow and digital control matter.
EZ Tankless Ultra HE Natural Gas Water Heater
Best for: Efficient whole-home heating with flexible venting
- Fuel Type
- Natural Gas
- Flow Rate
- 3.4 GPM
- Installation Location
- Indoor
- Dimensions
- 27 x 14.5 x 6.5 inches
- Use
- Whole House
- Venting Type
- Condensing
View on Amazon: EZ Tankless Ultra HE Natural Gas Water Heater Affiliate link
The EZ Ultra HE is an indoor natural gas tankless water heater designed for whole-home use. It features condensing technology to preheat incoming water using exhaust gas, improving efficiency. The unit provides up to 3.4 GPM at a 45°F rise. It includes a digital display and can be vented horizontally or vertically with standard PVC pipe. This model suits homes prioritizing efficiency and flexible venting options.
Pros
- Condensing technology preheats water using exhaust gas
- Flexible venting via 2-inch PVC or CPVC
- Includes back-draft prevention device and vent pipe
- Digital display for easy monitoring
Cons
- Lower flow rate of 3.4 GPM compared to competitors
- Bulky dimensions at 27 x 14.5 x 6.5 inches
- Indoor installation only
Good fit if
- You need efficient condensing technology
- You require flexible horizontal or vertical venting
- You want a whole-home solution with a digital display
Skip if
- You need a flow rate above 3.4 GPM
- You require outdoor installation
- You have limited space for a 27-inch unit
Verdict: EZ Tankless EZ Ultra HE Condensing Heater offers efficient condensing tech and flexible venting but has a lower flow rate and larger size than alternatives. It fits homes valuing efficiency over high flow.
Camplux 3.18 GPM Indoor Natural Gas Heater
Best for: Moderate flow needs with digital control
- Fuel Type
- Natural Gas
- Flow Rate
- 3.18 GPM
- BTU
- 82,000 BTU
- Installation Location
- Indoor
- Dimensions
- 22.8 x 14.3 x 14.3 inches
- Use
- Whole House
View on Amazon: Camplux 3.18 GPM Indoor Natural Gas Heater Affiliate link
The Camplux CA318BNG delivers 3.18 gallons per minute at 82,000 BTU. It is designed for indoor installation in whole-house settings. The unit features an oxygen-free copper heat exchanger and an LED digital display for temperature control. You get standard 1/2 inch NPT fittings and exhaust piping. This model suits households needing steady hot water for two to three simultaneous uses.
Pros
- 3.18 GPM flow rate for multiple fixtures
- 82,000 BTU heating capacity
- Oxygen-free copper heat exchanger
- LED digital display with Fahrenheit and Celsius options
- Includes exhaust piping for setup
Cons
- Lower flow rate compared to 4.21 GPM or 4.74 GPM alternatives
- Limited to indoor installation only
- No remote control or smart app connectivity listed
Good fit if
- You need reliable hot water for two to three simultaneous points of use
- You prefer a digital interface for precise temperature adjustments
- You are installing the unit in an indoor location
Skip if
- You require a flow rate above 4.0 GPM for high-demand households
- You need an outdoor-rated unit for exterior mounting
- You want smart home integration or remote control capabilities
Verdict: Camplux CA318BNG 3.18 GPM Natural Gas Heater provides steady hot water for moderate household usage. It fits buyers who prioritize copper durability and digital control over maximum flow speed.
Specifications side by side
| Spec | Forimo 4.74 GPM Natural Gas Tankless Water Heater | Forimo 4.74 GPM Indoor Natural Gas Water Heater | Forimo 4.21 GPM Natural Gas Indoor Heater | Forimo 4.21 GPM Natural Gas Tankless Water Heater | Forimo 4.74 GPM 18L Indoor Natural Gas Tankless Heater | EZ Tankless Ultra HE Natural Gas Water Heater | Camplux 3.18 GPM Indoor Natural Gas Heater |
|---|---|---|---|---|---|---|---|
| Fuel Type | Natural Gas (LNG) | Natural Gas | Natural Gas | Natural Gas | Natural Gas (LNG) | Natural Gas | Natural Gas |
| Flow Rate | 4.74 GPM | 4.74 GPM | 4.21 GPM | 4.21 GPM | 4.74 GPM | 3.4 GPM | 3.18 GPM |
| BTU | 81,888 BTU/hour | 123,000 BTU/hr | 68,000 BTU/hr | 68,000 BTU/hr | 81,888 BTU/hour | not stated | 82,000 BTU |
| Installation Location | Indoor | Indoor | Indoor | Indoor | Indoor | Indoor | Indoor |
| Temperature Control | Fahrenheit digital display | Fahrenheit digital display | 86°F-167°F | 86°F-167°F | Fahrenheit digital display | not stated | not stated |
| Dimensions | 21.7 x 13.8 x 13.8 inches | 22 x 13.8 x 13.8 inches | 25.4 x 14.4 x 14.4 inches | 14.4"W x 4.72"H x 25.4"L | 21.7 x 13.8 x 13.8 inches | 27 x 14.5 x 6.5 inches | 22.8 x 14.3 x 14.3 inches |
| Use | not stated | not stated | not stated | not stated | not stated | Whole House | Whole House |
| Venting Type | not stated | not stated | not stated | not stated | not stated | Condensing | not stated |
| Features | Digital Display | Digital Display | Digital Display | Digital Display | Digital Display | Digital Display | Digital Display |
| Weight | not stated | not stated | not stated | 23 pounds | 23.2 pounds | not stated | not stated |
| Size | 18L | not stated | not stated | not stated | 18L | not stated | 0.5-inch NPT |
| Color | Black(18L-Natural Gas) | Black | Black | Black | Black | White | Black |
| Model | CT1414-HWRSQ | HW-FM-18-LNG | HWRSQ-16L-LNG-2 | Tankless Water Heater-01 | CT1314-HWRSQ | EZ Ultra HE | CA318BNG |
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Frequently asked questions
Which Forimo model has the highest flow rate?
The Forimo 4.74 GPM models offer the highest flow rate in this list. Both the Best Overall and Best Premium picks deliver 4.74 gallons per minute. This higher flow supports simultaneous use of multiple fixtures, such as a shower and a kitchen sink, without significant temperature drops.
Are all these heaters designed for indoor installation?
Yes, every unit listed is rated for indoor installation. The data specifies indoor placement for all Forimo models and the EZ Tankless and Camplux options. You must ensure proper venting for natural gas combustion when placing these units inside your home, especially in enclosed spaces.
Does the EZ Tankless model use condensing technology?
Yes, the EZ Tankless Ultra HE uses condensing technology. This feature improves efficiency by capturing heat from exhaust gases. It also allows for flexible venting options, which can simplify installation compared to traditional non-condensing units that require specific vertical venting configurations.
Which option is best for homes needing lower flow?
The Camplux 3.18 GPM Indoor Natural Gas Heater is best for moderate flow needs. It delivers 3.18 gallons per minute, which suits smaller households or those using fewer fixtures simultaneously. This lower flow rate can be sufficient for homes where water conservation or lower gas usage is a priority.
Do these heaters include digital displays?
Yes, all listed models feature digital displays. This allows you to monitor and adjust water temperature precisely. The digital interface provides clear feedback on current settings, helping you maintain consistent water temperature across different usage scenarios without guessing the heat level.
How do the dimensions of the Forimo 18L models compare?
The Forimo 18L models are compact and similar in size. They share a width and length of 13.8 inches. The height varies slightly, with one model at 21.7 inches and another at 22 inches. These dimensions allow them to fit in standard utility spaces without requiring excessive room.
Is there a budget-friendly Forimo option available?
The Forimo 4.21 GPM Natural Gas Tankless Water Heater is labeled as the best budget pick. It offers 4.21 gallons per minute with digital controls. This model provides steady hot water for indoor residential use, making it a practical choice for buyers prioritizing value and reliable performance over maximum flow.
What fuel type do all these alternatives use?
All listed alternatives use natural gas as their fuel source. This includes the various Forimo models, the EZ Tankless, and the Camplux heater. You will need a natural gas supply line for installation. These units are not compatible with propane or electricity without specific adapter kits, which are not mentioned here.