Rheem vs FOGATTI Tankless Water Heaters: Which Brand Fits You?
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The rheem vs FOGATTI tankless water heater debate centers on two very different applications. Both provide continuous hot water without a storage tank. However, the Rheem unit is an electric model designed for whole-home residential use. The FOGATTI InstaShower 8 Plus is a propane-powered unit built specifically for RVs. You need to decide which fuel source and installation environment fit your needs.
Key differences
| Aspect | Rheem 18kW 240V Electric Tankless Water Heater | FOGATTI InstaShower 8 Plus RV Tankless Water Heater |
|---|---|---|
| Fuel Type | Electric | Propane |
| Voltage | 240 V | 12V DC |
| Use | Whole House | RV |
| Flow Rate | 4.4 GPM | 2.9 GPM |
| Wattage / BTU | 18 kW | 55,000 BTU |
Which one should you choose?
Choose Rheem 18kW 240V Electric Tankless Water Heater if
- You need hot water for multiple fixtures in a home
- You have a standard 240V electrical circuit available
- You want a higher flow rate for showers
Choose FOGATTI InstaShower 8 Plus RV Tankless Water Heater if
- You are installing in an RV or caravan
- You rely on propane gas for power
- You need a 12V DC electrical system
Verdict: Choose the Rheem if you are upgrading a residential home and need higher flow rates on 240V power. Pick the FOGATTI if you are outfitting an RV and require a propane solution that fits standard RV dimensions. Your fuel source and installation location dictate the correct choice.
Rheem vs FOGATTI Key Specs
Fuel Type
The Rheem 18kW model runs on 240V electricity, making it suitable for standard residential electrical systems. This requires a dedicated circuit and proper wiring infrastructure in your home. In contrast, the FOGATTI InstaShower 8 Plus uses propane gas. This fuel source is ideal for RVs or off-grid locations where electrical capacity is limited. Propane allows for continuous heating without drawing significant power from a battery or shore power. You must choose the fuel source that matches your available utility connections. Electric models offer precise control, while propane units provide independence from the grid.
Flow Rate
Flow rate determines how much hot water you get simultaneously. The Rheem unit delivers up to 4.4 GPM, which supports multiple fixtures like a shower and a sink running at the same time. This higher capacity makes it better for whole-home use. The FOGATTI model provides 2.9 GPM. This is sufficient for a single shower in an RV but may struggle if multiple outlets are open. If you need to fill a bathtub or run several taps, the Rheem’s higher flow rate is the practical choice. For a single user in a mobile setting, the FOGATTI output is adequate.
Intended Use
Application drives the design of these units. The Rheem is labeled for whole-house use, indicating it is built to handle the sustained demand of a residential family. It features durable copper immersion elements designed for long-term home installation. The FOGATTI is explicitly designed for RVs and caravans. It replaces traditional 6-gallon tank heaters in mobile living spaces. Its compact size and propane operation fit the constraints of travel trailers. You should select the Rheem for a permanent house installation and the FOGATTI only if you are outfitting a recreational vehicle or camper.
Voltage and Power
Electrical requirements differ significantly between these two models. The Rheem operates on 240V and draws 18 kW of power. This high wattage ensures rapid heating but requires a robust electrical panel. The FOGATTI runs on 12V DC, which is standard for RV electrical systems. This low voltage allows it to operate off vehicle batteries or a small inverter. You do not need heavy-duty wiring for the FOGATTI. However, the Rheem’s higher voltage enables its greater flow rate. Choose the FOGATTI if you are limited to 12V power sources.
Dimensions and Fit
Physical size affects where you can install the unit. The Rheem measures 14.5 x 18.5 x 3.5 inches. Its slim profile allows it to fit in closets or utility rooms without taking up much floor space. The FOGATTI is a cube, measuring 15 x 15 x 15 inches. It is designed to replace specific RV tank heaters with a 15x15 inch door opening. The Rheem is smaller in height and width, offering more flexibility for home mounting. The FOGATTI’s cubic shape is optimized for the standardized compartments found in travel trailers.
Temperature Control
Precision in temperature management varies by technology. The Rheem features an external digital thermostatic control with an LED display and ±1°F accuracy. This allows you to set exact water temperatures for comfort and safety. The FOGATTI uses staged combustion technology to manage heat, particularly at high altitudes. It includes a built-in pressure relief valve and automatic gas shut-off for safety. While the FOGATTI prioritizes safe operation in variable conditions, the Rheem offers finer manual adjustment for consistent household water temperature.
Choose your tankless water heater
Homeowners needing whole-house hot water
The Rheem 18kW unit delivers up to 4.4 GPM of hot water, sufficient for multiple fixtures in a residence. Its 240V electric operation integrates with standard home wiring. The external digital thermostat offers precise temperature control with ±1°F accuracy, ensuring consistent comfort for daily household routines without relying on gas lines.
RV owners seeking continuous showers
The FOGATTI InstaShower 8 Plus runs on propane, making it ideal for mobile living. It provides 2.9 GPM of continuous hot water, lasting over 40 minutes compared to limited tank reserves. The 12V DC power draw suits RV electrical systems, while high-altitude readiness ensures reliable performance up to 9,800 feet during travel.
Users wanting precise temperature settings
Precision matters for comfort. The Rheem features an external digital thermostatic control with LED display and ±1°F accuracy. This allows you to set exact water temperatures rather than relying on manual knobs. The self-modulation technology adjusts power to meet demand, maintaining your chosen temperature steadily across varying flow rates.
Campers needing easy installation
The FOGATTI unit includes a 15-inch door and remote controller, simplifying setup in tight RV spaces. It replaces standard 6-gallon tank heaters with a compact 15x15x15 inch footprint. Built-in safety features like forced exhaust and anti-freeze protection add reliability. The propane fuel source ensures you are not dependent on electrical outlets while camping.
The products compared
Rheem 18kW 240V Electric Tankless Water Heater
Best for: Whole-house electric hot water needs
- Fuel Type
- Electric
- Flow Rate
- 4.4 GPM
- Wattage
- 18 kW
- Voltage
- 240 V
- Temperature Control
- ±1°F
- Dimensions
- 3.5 x 14.5 x 18.5 inches
View on Amazon: Rheem 18kW 240V Electric Tankless Water Heater Affiliate link
This Rheem unit delivers 18 kW of power at 240 volts, supporting a flow rate of up to 4.4 GPM. It features an external digital thermostat with ±1°F accuracy and self-modulation technology that adjusts power to meet demand. The compact gray design measures 3.5 x 14.5 x 18.5 inches. It suits whole-house needs where electric infrastructure supports high wattage.
Pros
- 18 kW output for strong hot water performance
- ±1°F temperature control precision
- Self-modulation adjusts power to demand
- Field-serviceable copper heating elements
Cons
- Requires 240V electrical circuit
- 18.5-inch length needs vertical space
- No remote control included
Good fit if
- You have a 240V electrical panel
- You need whole-house hot water
- You want precise temperature control
Skip if
- You only have 120V outlets
- You need propane or gas
- You want a point-of-use unit
Verdict: Rheem 18kW Electric Tankless Water Heater suits homes with adequate electrical capacity needing reliable whole-house hot water. Its self-modulation and precise control make it a solid choice for consistent performance.
FOGATTI InstaShower 8 Plus RV Tankless Water Heater
Best for: RV high-altitude camping and travel
- Fuel Type
- Propane
- Flow Rate
- 2.9 GPM
- BTU
- 55,000 BTU
- Voltage
- 12V DC
- Certification
- CSA
- Dimensions
- 15 x 15 x 15 inches
View on Amazon: FOGATTI InstaShower 8 Plus RV Tankless Water Heater Affiliate link
This FOGATTI unit is a propane-powered tankless water heater designed for RV use. It delivers 2.9 GPM using 55,000 BTU of heat output. The device runs on 12V DC power and includes a 15-inch door and remote controller. It is CSA certified and built for high-altitude environments up to 9,800 feet. This model replaces standard 6-gallon tank heaters in most RVs.
Pros
- 55,000 BTU output provides continuous hot water
- High-altitude ready up to 9,800 feet
- Includes 15x15 inch door and 2m remote
- CSA certified with anti-freeze protection
Cons
- Limited to 2.9 GPM flow rate
- Requires 12V DC electrical connection
- Specific to RV applications only
Good fit if
- You need continuous hot water in an RV
- You travel to high-altitude destinations
- You want to replace a 6-gallon tank heater
Skip if
- You require a high-flow showerhead
- You need a residential whole-home unit
- You only have 240V AC power available
Verdict: FOGATTI InstaShower 8 Plus Propane RV Heater is a compact, propane-fueled solution for RVers who need reliable hot water on the road. It fits buyers prioritizing altitude performance and continuous flow over high volume.
Specifications side by side
| Spec | Rheem 18kW 240V Electric Tankless Water Heater | FOGATTI InstaShower 8 Plus RV Tankless Water Heater |
|---|---|---|
| Fuel Type | Electric | Propane |
| Flow Rate | 4.4 GPM | 2.9 GPM |
| BTU | not stated | 55,000 BTU |
| Wattage | 18 kW | not stated |
| Voltage | 240 V | 12V DC |
| Temperature Control | ±1°F | not stated |
| Certification | not stated | CSA |
| Dimensions | 3.5 x 14.5 x 18.5 inches | 15 x 15 x 15 inches |
| Use | Whole House | RV |
| Weight | 14.8 pounds | not stated |
| Size | Small | InstaShower 8 Plus |
| Color | Gray | InstaShower 8 Plus, Black |
| Model | RTEX-18 | FS08B1SBD |
Frequently asked questions
Is Rheem better for whole-house hot water?
Yes, the Rheem 18kW unit is designed for whole-house use. It delivers up to 4.4 GPM of hot water, which is sufficient for multiple fixtures in a residence. Its 240V electric operation integrates with standard home wiring, making it a reliable choice for consistent performance in larger homes.
Can I use FOGATTI for my RV?
Yes, the FOGATTI InstaShower 8 Plus is specifically built for RVs. It runs on propane, which is ideal for travel and camping. The compact design fits well in mobile spaces, allowing you to have reliable hot water on the road without relying on electrical hookups at your campsite.
What fuel type does the Rheem heater use?
The Rheem 18kW model runs on 240V electricity. This requires a dedicated circuit and proper wiring infrastructure in your home. It is an electric unit, so it does not need gas lines or venting, which simplifies installation for homeowners with adequate electrical capacity.
Does the FOGATTI heater work at high altitudes?
Yes, the FOGATTI InstaShower 8 Plus is noted for its altitude performance. It is a propane-fueled solution that maintains continuous flow even when camping at higher elevations. This makes it a practical choice for RVers who frequently travel to mountainous regions or high-altitude destinations.
How big is the Rheem tankless water heater?
The Rheem RTEX-18 is a small unit measuring 18.5 inches in length, 14.5 inches in width, and 3.5 inches in height. It weighs 14.8 pounds. Its compact gray casing allows for easy mounting in tight spaces like closets or utility rooms without taking up much room.
Is the FOGATTI heater portable?
The FOGATTI InstaShower 8 Plus measures 15 inches by 15 inches by 15 inches. Its cubic shape and propane fuel source make it suitable for mobile applications. It is designed for RVers who need a compact, self-contained hot water solution that travels easily with their vehicle.
Which brand is better for residential homes?
Rheem is the better choice for residential homes. The 18kW model provides reliable whole-house hot water with precise control via an external digital thermostat. It suits homes with adequate electrical capacity, offering consistent performance for daily household needs like showers and laundry.