Forimo 4.74 GPM Indoor Natural or Forimo 18L Indoor Propane Tankless? Which Forimo Model to Buy
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The forimo 4 74 gpm indoor natural vs 18l indoor propane tankless comparison highlights two distinct units from the same brand. Both deliver 4.74 GPM and feature LED displays, stainless steel bodies, and indoor installation capabilities. They share similar safety protections and copper heat exchangers. The primary difference lies in their fuel source. One model runs on natural gas, while the other uses propane. This choice dictates your venting needs and gas line compatibility.
Key differences
| Aspect | Forimo 4.74 GPM Indoor Natural Gas Water Heater | Forimo 18L Indoor Propane Tankless Heater |
|---|---|---|
| Fuel Type | Natural Gas | Propane |
| BTU Output | 123,000 BTU/hr | 68,000 BTU/hr |
| Venting | 6 cm (2.3 in) diameter exhaust | 2.5 in horizontal vent pipe |
| Dimensions | 22 x 13.8 x 13.8 inches | 25.4 x 14.4 x 14.4 inches |
Which one should you choose?
Choose Forimo 4.74 GPM Indoor Natural Gas Water Heater if
- You have a natural gas line available for connection
- You need higher heat output for faster water heating
- You prefer a more compact unit with a 6 cm exhaust
Choose Forimo 18L Indoor Propane Tankless Heater if
- You use propane tanks for your home energy
- You require a lower minimum water pressure of 3.6 PSI
- You are installing a system with horizontal venting constraints
Verdict: Choose the natural gas model if you have a direct gas line and want higher BTU output. Select the propane model if you rely on propane tanks or need lower water pressure requirements. Both units provide steady temperature control and efficient heating for indoor use.
Natural Gas vs Propane Forimo Models
Fuel type
The Forimo 4.74 GPM Indoor Natural Gas Water Heater is designed exclusively for natural gas (LNG). It requires a dedicated natural gas supply line for operation. In contrast, the Forimo 18L Indoor Propane Tankless Heater is built specifically for propane (LPG). You must connect this unit to a propane tank or supply system. Both models are incompatible with the other fuel type. You need to verify your existing fuel infrastructure before purchasing. Choosing the wrong fuel type will prevent the unit from functioning. Ensure your home has the correct gas source for the specific model you select.
Power output
Heating capacity differs significantly between these two units. The natural gas model delivers a maximum power output of 123,000 BTU per hour. This higher output supports consistent hot water delivery for multiple fixtures simultaneously. The propane model provides 68,000 BTU per hour. While still sufficient for many households, the lower BTU rating means it relies on different combustion efficiency. Both units claim to handle two to three points of simultaneous use. However, the natural gas unit has nearly double the thermal power input, which may affect performance in very cold incoming water conditions.
Water pressure
Minimum water pressure requirements vary between the two models. The natural gas heater needs a minimum of 0.2 MPa, which equals 29 PSI. It operates within a range of 0.2 to 0.8 MPa. The propane model requires significantly less pressure, needing only 3.6 PSI to function. This makes the propane unit suitable for homes with low water pressure or gravity-fed systems. If you live in an area with weak municipal pressure or use a well pump, the propane model offers easier operation without additional booster pumps.
Dimensions
Physical size and footprint are important for indoor installation space. The natural gas unit measures 22 inches in height, with a width and length of 13.8 inches. The propane model is taller and slightly wider, measuring 25.4 inches in height, with a width and length of 14.4 inches. Both units are compact compared to traditional tank heaters. However, the propane model takes up more vertical space and requires a larger clearance area. Measure your installation spot carefully to ensure the propane unit fits comfortably in your designated location.
Venting
Exhaust venting specifications differ for each model. The natural gas heater comes with a 6 cm diameter exhaust vent, which is approximately 2.3 inches. The propane model includes a 2.5-inch horizontal vent pipe. Both require proper ventilation and dedicated exhaust pipes to vent combustion gases outdoors safely. You must follow local codes for venting. The propane model explicitly mentions a horizontal vent configuration in its description. Verify your existing venting setup matches the required diameter and orientation for your chosen model to ensure safe and efficient operation.
Choose based on your gas supply type
Home with existing natural gas line
This model runs exclusively on natural gas. It delivers 123,000 BTU per hour at 4.74 GPM. The higher power output supports simultaneous use in two to three fixtures. It requires 0.2 MPa minimum water pressure. This unit fits standard indoor plumbing connections for natural gas supply.
Renter or cabin with propane tank
This unit is designed for propane (LPG) fuel only. It outputs 68,000 BTU per hour while maintaining the same 4.74 GPM flow rate. It operates with a very low minimum water pressure of just 3.6 PSI. This makes it suitable for locations with limited water pressure or remote setups.
User needing higher temperature range
The propane model allows temperature adjustment between 86°F and 167°F. This wide range offers precise control for different needs. Both units share the same flow rate and safety features. However, the specific temperature control limits differ, making the propane version preferable if you require that specific upper limit.
The products compared
Forimo 4.74 GPM Indoor Natural Gas Water Heater
Best for: Indoor homes needing multi-fixture hot water access
- 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 of hot water using natural gas. It features a 123,000 BTU/hr output and an indoor installation design. The stainless steel body includes an oxygen-free copper water tank for durability. You get steady temperature control via an LED digital display. It requires a minimum water pressure of 0.2 MPa. This model is built for simultaneous use at two to three fixtures in your home.
Pros
- High flow rate of 4.74 GPM for multiple fixtures
- 123,000 BTU/hr heating capacity for rapid hot water
- Stainless steel construction with copper water tank
- LED digital display for precise temperature adjustment
- Compact indoor design saves over 50% space
Cons
- Requires 0.2 MPa minimum water pressure to operate
- Dedicated exhaust venting is mandatory for indoor use
- Must drain residual water in cold weather if unused
Good fit if
- You need hot water for two to three simultaneous outlets
- You have adequate ventilation for indoor exhaust venting
- You prefer digital temperature control over analog dials
Skip if
- You only have propane fuel available instead of natural gas
- Your water pressure is consistently below 0.2 MPa
- You require outdoor installation without venting modifications
Verdict: Forimo 18L Natural Gas Tankless Water Heater provides reliable high-flow hot water for indoor households with proper venting. It suits users needing simultaneous fixture access and digital temperature precision.
Forimo 18L Indoor Propane Tankless Heater
Best for: indoor propane-powered hot water needs
- Fuel Type
- Propane
- Flow Rate
- 4.74 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 18L Indoor Propane Tankless Heater Affiliate link
This Forimo unit delivers 4.74 GPM of hot water using propane fuel. It features a 68,000 BTU output and an LED 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 or three fixtures. You should choose this model if you need a propane-powered solution for your bathroom or kitchen.
Pros
- 4.74 GPM flow rate for multiple fixtures
- 68,000 BTU/hr heating capacity
- LED digital display for precise temperature adjustment
- Built-in anti-freezing and over-heating protection
Cons
- Requires specific propane fuel, not natural gas
- Limited to indoor installation only
- Must drain residual water in cold weather if unused
Good fit if
- You are installing a tankless heater in an indoor location
- You have access to a propane supply line
- You need hot water for two to three simultaneous points
Skip if
- You only have natural gas available
- You require outdoor installation capabilities
- You need a unit compatible with natural gas fuel
Verdict: Forimo 18L Propane Tankless Water Heater fits homes with propane lines needing reliable indoor hot water. It suits users who want precise temperature control via its digital display.
Specifications side by side
| Spec | Forimo 4.74 GPM Indoor Natural Gas Water Heater | Forimo 18L Indoor Propane Tankless Heater |
|---|---|---|
| Fuel Type | Natural Gas | Propane |
| Flow Rate | 4.74 GPM | 4.74 GPM |
| BTU | 123,000 BTU/hr | 68,000 BTU/hr |
| Installation Location | Indoor | Indoor |
| Temperature Control | Fahrenheit digital display | 86°F-167°F |
| Dimensions | 22 x 13.8 x 13.8 inches | 25.4 x 14.4 x 14.4 inches |
| Features | Digital Display | Digital Display |
| Color | Black | Black |
| Model | HW-FM-18-LNG | HWRSQ-18L-LPG-2 |
Frequently asked questions
Can I install the Forimo 18L propane heater indoors?
Yes, the Forimo 18L Indoor Propane Tankless Heater is designed for indoor installation. It features a digital display and stainless steel construction. Ensure you have proper ventilation and a dedicated propane line. The unit measures 14.4 inches wide and 25.4 inches tall. Follow local codes for safe indoor placement.
Does the natural gas model have a digital display?
Yes, the Forimo 4.74 GPM Indoor Natural Gas Water Heater includes a digital display. This feature allows you to monitor and adjust water temperature precisely. The unit is black and fits indoor spaces. It requires a natural gas supply. The display helps you maintain consistent output for multiple fixtures.
What is the difference between the two Forimo models?
The main difference is the fuel source. One model uses natural gas, while the other uses propane. Both deliver 4.74 GPM and have digital displays. The propane model is slightly taller and wider. Choose based on your existing gas line type. Both are built for indoor use with similar safety features.
Is the Forimo natural gas heater suitable for multiple bathrooms?
Yes, it is best for indoor homes needing multi-fixture access. It delivers 4.74 GPM, which supports simultaneous use in two to three fixtures. The digital display helps manage temperature settings. Ensure you have proper venting. This model provides reliable high-flow hot water for busy households.
What are the dimensions of the propane tankless heater?
The Forimo 18L Indoor Propane Tankless Heater measures 14.4 inches in width and length. Its height is 25.4 inches. It is black and designed for indoor installation. These dimensions help you plan the mounting space. Ensure your area has adequate clearance and proper ventilation for safe operation.
Which Forimo model is better for high flow needs?
Both models deliver 4.74 GPM, so flow rates are identical. The natural gas model offers higher BTU output for stronger heating. The propane model provides precise temperature control via its digital display. Choose based on your fuel availability. Both are suitable for indoor use with multiple simultaneous fixtures.
Do I need special venting for these units?
Yes, both models are designed for indoor installation and require proper venting. The natural gas model needs a dedicated gas line and appropriate exhaust. The propane model also requires safe indoor placement with ventilation. Check local building codes. Proper venting ensures efficient operation and safety for your home.