6 Best Alternatives to the Eemax SPEX3512 FlowCo 3.5 Kilowatt (2026)
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The Eemax SPEX3512 FlowCo 3.5 Kilowatt is a compact point-of-use heater designed for tight spaces. If you are searching for eemax spex3512 flowco 3 5 kilowatt alternatives, you might want more capacity or different installation flexibility. This unit provides reliable heat for single sinks but lacks the power for whole-house needs. Its small footprint fits under counters, yet it only works with 120V circuits. Some buyers need higher flow rates or dual-fuel options for RVs. Others may prefer a mini-tank for stored hot water instead of on-demand heating. The alternatives listed here share overlapping specifications with the original Eemax model. We selected these products because they offer comparable voltage, fuel type, or physical dimensions. Each option addresses specific gaps in the SPEX3512 design. You can choose a larger unit for multiple fixtures or a different form factor for unique spaces. This list covers electric heaters that match the core requirements while offering varied capacities. The goal is to help you find a spec that fits your exact plumbing and electrical setup. All listed products are evaluated based on their published technical data.
Our top pick: Eemax FlowCo 3.5 kW 120V Point of Use Water Heater.
How these alternatives compare
Thermomate 6.5-Gallon Under-Sink Electric Mini-Tank
The Thermomate 6.5-Gallon Mini-Tank stores hot water, unlike the Eemax FlowCo which heats on demand. This tank holds 6.5 gallons of ready-to-use water, while the Eemax provides continuous flow limited by its 3.5 kW output. The Thermomate is larger, measuring 21.2 inches tall, compared to the Eemax’s 9.75-inch height. You get stored reserves with the Thermomate, but lose the endless supply of the tankless Eemax. Choose the Thermomate if you need hot water even when the heater is off, or for brief high-demand bursts. The Eemax remains better for unlimited hot water during longer showers or running taps.
Suburban 6-Gallon Gas and Electric RV Water Heater
The Suburban 6-Gallon RV Water Heater offers dual-fuel flexibility, heating with either propane or 120V electricity. The Eemax SPEX3512 runs only on 120V electric power. This makes the Suburban suitable for RVs or cabins without reliable grid power. The Suburban is a tank unit with a 6-gallon capacity, whereas the Eemax is a compact tankless device. The Suburban weighs more at 32.9 pounds compared to the Eemax’s 3.1 pounds. You gain fuel versatility with the Suburban but lose the space-saving, on-demand nature of the Eemax. Pick the Suburban for mobile or off-grid applications where propane is available.
Rheem 18kW 240V Electric Tankless Water Heater
The Rheem RTEX-18 is a high-power whole-house unit, while the Eemax is a low-power point-of-use heater. The Rheem operates on 240V with 18 kW of power, significantly more than the Eemax’s 120V and 3.5 kW. This allows the Rheem to serve multiple fixtures simultaneously, whereas the Eemax is best for single sinks. The Rheem is larger at 18.5 inches long, compared to the Eemax’s 3-inch length. You get whole-house capability with the Rheem, but require a 240V circuit. The Eemax is ideal for single fixtures where 240V wiring is not available. Choose the Rheem for whole-home needs.
Camplux 6-Gallon 120V Mini-Tank Water Heater
The Camplux 6-Gallon Mini-Tank provides stored hot water, contrasting with the Eemax’s continuous on-demand heating. It holds 6 gallons of pre-heated water, while the Eemax heats water as it flows through. The Camplux is larger, measuring 18 inches tall, compared to the Eemax’s 9.75-inch height. It weighs 25.4 pounds, much heavier than the Eemax’s 3.1 pounds. You gain hot water reserves with the Camplux, but lose the endless flow of the Eemax. The Camplux is suitable for low-demand applications where hot water runs are short. Choose the Camplux if you prefer stored hot water over on-demand heating for single sink use.
VEVOR 6-Gallon 1600W Electric Water Heater
The VEVOR 6-Gallon Electric Water Heater stores hot water, unlike the Eemax FlowCo which heats on demand. It holds 6 gallons of ready water, while the Eemax provides continuous flow limited by its 3.5 kW output. The VEVOR is larger, measuring 22.6 inches tall, compared to the Eemax’s 9.75-inch height. It weighs 30.9 pounds, significantly more than the Eemax’s 3.1 pounds. You get stored reserves with the VEVOR, but lose the space-saving, on-demand nature of the Eemax. The VEVOR is practical for low-demand applications where a 120V connection is available. Choose the VEVOR if you need hot water reserves, or stick with the Eemax for endless flow.
Thermomate 18kW Electric Tankless Water Heater
The Thermomate 18kW Electric Tankless Heater provides high-flow whole-house heating, while the Eemax is a low-power point-of-use unit. The Thermomate operates on 240V with 18 kW, far exceeding the Eemax’s 120V and 3.5 kW. This allows the Thermomate to serve multiple fixtures, whereas the Eemax is best for single sinks. The Thermomate is larger at 17.1 inches tall, compared to the Eemax’s 9.75-inch height. You get whole-house capability with the Thermomate, but require a 240V circuit. The Eemax is ideal for single fixtures where 240V wiring is not available. Choose the Thermomate for whole-home needs.
Quick picks
Our 7 picks
Eemax FlowCo 3.5 kW 120V Point of Use Water Heater
Best for: single sink point-of-use hot water
- Fuel Type
- Electric
- Wattage
- 3.5 Kilowatt
- Installation Location
- Point of Use
- Voltage
- 120 Volt
- Dimensions
- 9.75 x 5 x 3 inches
- Weight
- 3.1 pounds
View on Amazon: Eemax FlowCo 3.5 kW 120V Point of Use Water Heater Affiliate link
This compact electric water heater delivers on-demand hot water at a sink or small appliance. It operates on 120 volts with 3.5 kilowatts of power. The unit provides a 41°F temperature rise at 0.5 GPM. Its small footprint of 9.75 x 5 x 3 inches allows flexible mounting. You get self-diagnostics and SafeStart technology for reliable operation. It is designed for point-of-use installation where space is tight.
Pros
- 3.5 Kilowatt electric heating element
- 120 Volt power requirement
- Compact 9.75 x 5 x 3 inch dimensions
- Mounts in any orientation
- Self-diagnostics and intelligent controls
Cons
- Low 3.5 Kilowatt output limits flow rate
- Requires 120 Volt circuit only
- Cold water inlet only
Good fit if
- You need hot water for a single sink
- You have limited space under a counter
- You want a 120 Volt installation
Skip if
- You need to heat water for a shower
- You require multiple simultaneous fixtures
- You only have a 240 Volt circuit
Verdict: Eemax SPEX3512 3.5kW 120V Point-of-Use Heater fits tight spaces and single-fixture needs. It provides reliable heat for sinks where low flow is acceptable.
Thermomate 6.5-Gallon Under-Sink Electric Mini-Tank
Best for: Under-sink hot water needs
- Fuel Type
- Electric
- Wattage
- 1.44 kW
- Capacity
- 6.5 Gallons
- Voltage
- 120V
- Temperature Control
- 50°F to 149°F
- Certification
- UL Listed
View on Amazon: Thermomate 6.5-Gallon Under-Sink Electric Mini-Tank Affiliate link
The ThermoMate 6.5 Gallon Mini Tank is a point-of-use electric water heater designed for under-sink installation. It operates on 120V power with a 1.44 kW heating element. The unit holds 6.5 gallons of water and features a glass-lined tank for durability. You get adjustable temperature settings ranging from 50°F to 149°F. This compact unit suits small households needing localized hot water without complex plumbing.
Pros
- 6.5 gallon capacity provides sufficient hot water for sinks
- 120V plug-in connection simplifies installation
- Adjustable thermostat with high temperature limit protection
Cons
- 1.44 kW heating element is slower than whole-home units
- 26.5 pound weight requires sturdy mounting
- 1-year parts warranty is shorter than industry standards
Good fit if
- You need hot water for a single sink
- You have a standard 120V outlet nearby
- You want a compact unit under a counter
Skip if
- You require high flow rates for showers
- You need a whole-house heating solution
- You want a longer warranty coverage
Verdict: ThermoMate 6.5 Gallon Mini Tank delivers reliable point-of-use heating for small spaces. It fits users who prioritize easy installation and compact size over high capacity.
Suburban 6-Gallon Gas and Electric RV Water Heater
Best for: RVers needing compact dual-fuel hot water
- Fuel Type
- Electric, Gas
- BTU
- 12,000 BTU/h
- Wattage
- 1,440 W
- Capacity
- 6 Gallon
- Dimensions
- 12.69 x 12.69 x 19.19 in
- Use
- RV
View on Amazon: Suburban 6-Gallon Gas and Electric RV Water Heater Affiliate link
The Suburban SW6DE is a 6-gallon tank water heater designed for RV use. It features a porcelain-lined steel tank and dual fuel options, including a 12,000 BTU gas burner and a 1,440-watt electric element. This setup allows you to heat water using either propane or campsite power. Its compact 12.69-inch square footprint fits standard RV compartments. The unit includes a replaceable anode rod for corrosion protection and offers a 2-year limited warranty.
Pros
- Dual fuel capability with 12,000 BTU gas and 1,440W electric elements
- Porcelain-lined steel tank for durable construction
- Replaceable anode rod doubles as a drain for easy maintenance
- Compact 12.69-inch square dimensions fit tight RV spaces
Cons
- Smaller 6-gallon capacity limits continuous hot water supply
- Requires both gas and electrical connections for full functionality
- Shorter 2-year limited warranty compared to residential units
Good fit if
- You need a reliable hot water source for an RV or camper
- You want the flexibility to switch between propane and electric power
- You have a standard 12.69-inch square compartment for installation
Skip if
- You require a high-flow tankless system for multiple simultaneous showers
- You only have access to electricity and no gas supply
- You need a larger capacity for whole-house residential use
Verdict: Suburban 6-Gallon RV Water Heater provides essential hot water for RV travelers who value dual-fuel flexibility and compact sizing. It is a practical solution for campers who need reliable heating from either propane or 120V power.
Rheem 18kW 240V Electric Tankless Water Heater
Best for: whole-house electric hot water
- 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
The Rheem RTEX-18 is an 18 kW electric tankless water heater designed for whole-house use. It delivers up to 4.4 GPM at 240 V. The unit features copper immersion heating elements and an external digital thermostat with ±1°F accuracy. Its slim profile measures 3.5 x 14.5 x 18.5 inches. This model suits households needing reliable, on-demand hot water with precise temperature control.
Pros
- 18 kW power output for whole-house supply
- Up to 4.4 GPM flow rate
- Digital thermostat with ±1°F accuracy
- Copper immersion heating elements
Cons
- Requires 240 V electrical connection
- Heavier at 14.8 pounds
- Limited to electric fuel type
Good fit if
- You need a whole-house electric solution
- You want precise temperature control
- You have 240 V wiring available
Skip if
- You only have 120 V outlets
- You need a point-of-use unit
- You prefer gas fuel type
Verdict: Rheem RTEX-18 18kW Tankless Heater provides high flow and precise control for whole-house electric setups. It fits homes with 240 V capacity needing reliable on-demand hot water.
Camplux 6-Gallon 120V Mini-Tank Water Heater
Best for: single sink point-of-use hot water
- Fuel Type
- Electric
- Wattage
- 1,440 W
- Capacity
- 6 gallons
- Voltage
- 120 V
- Temperature Control
- 50°F to 149°F
- Certification
- UL, CSA
View on Amazon: Camplux 6-Gallon 120V Mini-Tank Water Heater Affiliate link
The Camplux ME60 is a 6-gallon point-of-use water heater designed for under-sink installation. It operates on 120V power with 1,440W heating elements. The unit features a glass-lined tank and adjustable thermostat settings ranging from 50°F to 149°F. It includes UL and CSA certifications for safety. This compact electric heater suits single-fixture applications where space is limited and 120V access is available.
Pros
- 6-gallon capacity provides immediate hot water for sinks
- 120V plug-in design allows simple electrical connection
- Glass-lined tank offers corrosion resistance
- Adjustable thermostat controls water temperature from 50°F to 149°F
- UL and CSA certified for safety compliance
Cons
- 1,440W heating element provides slower recovery than higher-wattage models
- 6-gallon capacity is limited for multiple simultaneous fixtures
- Requires 120V outlet which may need dedicated circuit installation
Good fit if
- You need hot water for a single sink or vanity
- You have a 120V outlet available near the installation site
- You want a compact unit that fits under standard cabinetry
Skip if
- You require hot water for multiple fixtures simultaneously
- Your electrical system only supports 240V circuits
- You need rapid recovery rates for high-demand usage
Verdict: Camplux 6-Gallon 120V Electric Mini Tank delivers reliable point-of-use heating for low-demand applications. It fits well in tight spaces where 120V power is accessible, making it suitable for bathroom vanities or kitchen sinks.
VEVOR 6-Gallon 1600W Electric Water Heater
Best for: single sink or RV point-of-use heating
- Fuel Type
- Electric
- Wattage
- 1600 W
- Capacity
- 6 gal
- Voltage
- 120 V
- Dimensions
- 22.6 x 14.2 x 14.2 inches
- Weight
- 30.9 pounds
View on Amazon: VEVOR 6-Gallon 1600W Electric Water Heater Affiliate link
The VEVOR 6-gallon electric water heater offers 1600W heating power on a 120V circuit. It features a 20 mm foam insulation layer to reduce heat loss and an enamel interior for corrosion resistance. An LED display and rotary knob provide clear temperature control. This compact unit is designed for point-of-use installation under sinks or in RVs, making it suitable for single apartments or guest bathrooms.
Pros
- 1600W heating element for fast temperature recovery
- 20 mm thick foam insulation minimizes heat loss
- LED display shows heating status clearly
- IPX4 waterproof rating for safe indoor use
- Enamel interior resists corrosion for longevity
Cons
- 1600W is lower power than whole-home units
- 6-gallon capacity limits continuous hot water supply
- Rotary knob lacks precise digital temperature setting
Good fit if
- You need a supplementary hot water source for a kitchen sink
- You are installing in an RV or small apartment
- You want a 120V unit that fits under a counter
Skip if
- You require high-volume hot water for multiple simultaneous showers
- You need a unit with smart app connectivity
- You are looking for a whole-house heating solution
Verdict: VEVOR 6 Gal 1600W Electric Tank is a practical point-of-use solution for low-demand applications. It fits well in tight spaces where a 120V connection is available and only a small amount of hot water is needed.
Thermomate 18kW Electric Tankless Water Heater
Best for: High-flow whole-house heating needs
- Fuel Type
- Electric
- Flow Rate
- Up to 4.4GMP
- Wattage
- 18kW
- Installation Location
- Indoor
- Voltage
- 240V
- Temperature Control
- 80°F to 140°F, ±1°F
View on Amazon: Thermomate 18kW Electric Tankless Water Heater Affiliate link
This ThermoMate unit delivers instant hot water at up to 4.4 gallons per minute. It operates on 240 volts and draws significant power, requiring two 40-amp breakers. The compact design mounts on walls to save floor space. You get precise temperature control from 80°F to 140°F in 1-degree increments. The digital display shows current settings clearly. It is built for indoor use where you need high flow rates.
Pros
- High flow rate of up to 4.4 GPM
- Precise digital temperature control in 1° increments
- Compact wall-mounted design saves space
- ETL certified for safety
Cons
- Requires two 40-amp double-pole breakers
- Needs 8AWG wire gauge for installation
- High amperage draw limits circuit options
Good fit if
- You need high flow for a whole house
- You have a dedicated 240V electrical circuit
- You want precise temperature adjustments
Skip if
- You only have a standard 120V outlet
- You cannot install heavy-duty breakers
- You need a portable or temporary unit
Verdict: ThermoMate 18kW 240V Electric Tankless Heater fits homes with robust electrical infrastructure. It provides reliable high-volume hot water for busy households. You should choose it if you can support the power requirements.
Specifications side by side
| Spec | Eemax FlowCo 3.5 kW 120V Point of Use Water Heater | Thermomate 6.5-Gallon Under-Sink Electric Mini-Tank | Suburban 6-Gallon Gas and Electric RV Water Heater | Rheem 18kW 240V Electric Tankless Water Heater | Camplux 6-Gallon 120V Mini-Tank Water Heater | VEVOR 6-Gallon 1600W Electric Water Heater | Thermomate 18kW Electric Tankless Water Heater |
|---|---|---|---|---|---|---|---|
| Fuel Type | Electric | Electric | Electric, Gas | Electric | Electric | Electric | Electric |
| Flow Rate | not specified | not specified | not specified | 4.4 GPM | not specified | not specified | Up to 4.4GMP |
| BTU | not specified | not specified | 12,000 BTU/h | not specified | not specified | not specified | not specified |
| Wattage | 3.5 Kilowatt | 1.44 kW | 1,440 W | 18 kW | 1,440 W | 1600 W | 18kW |
| Installation Location | Point of Use | not specified | not specified | not specified | not specified | not specified | Indoor |
| Capacity | not specified | 6.5 Gallons | 6 Gallon | not specified | 6 gallons | 6 gal | not specified |
| Voltage | 120 Volt | 120V | not specified | 240 V | 120 V | 120 V | 240V |
| Temperature Control | not specified | 50°F to 149°F | not specified | ±1°F | 50°F to 149°F | not specified | 80°F to 140°F, ±1°F |
| Certification | not specified | UL Listed | not specified | not specified | UL, CSA | not specified | ETL |
| Dimensions | 9.75 x 5 x 3 inches | 17.7"H x 17.7"W x 14.6"D | 12.69 x 12.69 x 19.19 in | 3.5 x 14.5 x 18.5 inches | 18 x 15.75 x 15.5 inches | 22.6 x 14.2 x 14.2 inches | 17.12" x 13.12" x 3.12" |
| Use | not specified | Under Sink | RV | Whole House | not specified | not specified | not specified |
| Weight | 3.1 pounds | 26.5 pounds | 32.9 pounds | 14.8 pounds | 25.4 pounds | 30.9 pounds | not specified |
| Color | White | white,blue | Steel | Gray | White | Gray | Gray |
| Model | SPEX3512 | ES700 | 5239A | RTEX-18 | ME60 | FJI-POR-30S2 | ET180 |
| Size | not specified | 6.5 Gallon | 6 Gallon | Small | not specified | 6 Gal | 240V/18kW |
Frequently asked questions
Can I use a mini-tank instead of a tankless unit for a single sink?
Yes, you can. The Thermomate 6.5-Gallon and Camplux 6-Gallon models provide stored hot water for low-demand fixtures. These units fit under sinks and connect to standard 120V outlets. They are ideal if you prefer ready-to-use water over on-demand heating. The tank capacity ensures consistent temperature during short usage periods.
What is the best whole-house alternative to the Eemax FlowCo?
The Rheem RTEX-18 and Thermomate ET180 are suitable whole-house options. Both deliver 18 kW of power at 240V. They provide high flow rates for multiple fixtures. These units require robust electrical infrastructure. They are significantly larger than the 3.5 kW point-of-use model but handle whole-home demands effectively.
Is there a dual-fuel option for RVs or mobile homes?
Yes, the Suburban 6-Gallon unit supports both electric and gas heating. It operates on propane or 120V power. This flexibility is useful for RV travelers. The steel construction is compact, measuring 12.7 inches on each side. It provides essential hot water in mobile environments where fuel sources may vary.
How do the dimensions of these alternatives compare to the Eemax?
The Eemax is extremely compact at 5 by 9.75 inches. Most alternatives are larger. The Rheem tankless unit is 14.5 by 18.5 inches. Mini-tanks like the Thermomate measure 14.6 by 21.2 inches. The Suburban unit is cubic at 12.7 inches per side. You need more space for higher-capacity models.
Can I install these heaters myself without professional help?
Installation depends on the unit type and your electrical setup. Point-of-use mini-tanks often connect to standard 120V outlets. Tankless whole-house models require 240V circuits and may need a licensed electrician. Always verify voltage requirements and local codes. Compact units are generally easier to mount in tight spaces like under sinks.
What is the weight difference between tankless and tank models?
Tankless units are lighter. The Eemax weighs 3.1 pounds, and the Rheem weighs 14.8 pounds. Mini-tanks are heavier due to water storage. The Thermomate 6.5-Gallon weighs 26.5 pounds, and the Camplux weighs 25.4 pounds. The Suburban RV unit is heaviest at 32.9 pounds. Consider mounting strength when choosing.
Are there gray-colored options available for these alternatives?
Yes, several models come in gray. The Rheem RTEX-18 and Thermomate ET180 are gray. The VEVOR 6-Gallon unit is also gray. Most other options, like the Eemax and Camplux, are white. The Suburban unit features a steel finish. Color choice depends on your installation visibility and aesthetic preference.