Thermomate or Suburban? Tankless Water Heaters Compared in 2026
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You are comparing the thermomate vs suburban tankless water heater options for your home or RV. Both units provide compact hot water storage near the point of use. The main difference lies in their fuel source and intended application. One is a residential electric mini-tank, while the other is a dual-fuel unit built for recreational vehicles. You need to match the power source and installation space to your specific needs.
Key differences
| Aspect | Thermomate 6.5-Gallon Under-Sink Electric Mini-Tank | Suburban 6-Gallon Gas and Electric RV Water Heater |
|---|---|---|
| Fuel Type | Electric only | Gas and Electric |
| Capacity | 6.5 Gallons | 6 Gallons |
| Wattage | 1.44 kW | 1,440 Watts (electric element) |
| Use Case | Under Sink | RV |
| Tank Lining | Glass-lined | Porcelain-lined |
| Dimensions | 17.7 x 17.7 x 14.6 inches | 12.7 x 12.7 x 19.19 inches |
Which one should you choose?
Choose Thermomate 6.5-Gallon Under-Sink Electric Mini-Tank if
- You need a dedicated under-sink heater for a residential kitchen or bathroom.
- You want a slightly larger 6.5-gallon capacity for point-of-use hot water.
- You only have access to a standard 120V electrical outlet.
Choose Suburban 6-Gallon Gas and Electric RV Water Heater if
- You are outfitting an RV and need flexibility between gas and electric power.
- You require a narrower footprint to fit into tight RV cabinetry.
- You prefer a porcelain-lined tank with a replaceable anode rod for maintenance.
Verdict: Choose the Thermomate if you are installing a point-of-use heater in a home with standard electrical access. Select the Suburban model if you are equipping an RV where space is tight and dual-fuel capability is essential.
Thermomate vs Suburban Key Specs
fuel type
Thermomate relies on standard 120V electricity, making it a simple plug-in solution for residential under-sink use. You just connect it to a standard outlet. Suburban offers a dual-fuel approach with gas and electric options. This flexibility suits RV environments where you might switch between shore power and propane. If you need gas capability for off-grid camping, Suburban is the clear choice. For pure residential electric convenience, Thermomate is simpler. The fuel difference defines their primary use cases.
capacity
Thermomate provides 6.5 gallons of stored hot water. This slightly larger volume helps sustain usage at a single point, like a bathroom sink. Suburban offers 6 gallons. While the difference is small, the larger tank in Thermomate may handle slightly higher demand in a home setting. However, Suburban’s gas recovery rate is faster when using propane. For pure storage volume, Thermomate has a slight edge. For rapid reheating on gas, Suburban performs better. Both are compact units designed for point-of-use applications.
installation location
Thermomate is designed for under-sink or counter mounting in homes. Its dimensions are 17.7 inches by 17.7 inches by 14.6 inches. It plugs into a 120V outlet. Suburban is built for RV interiors. Its footprint is smaller, roughly 12.7 inches square, with a height of 19.19 inches. It fits standard RV cutouts. If you are installing in a house kitchen or bath, Thermomate fits better. If you are outfitting an RV cabinet, Suburban’s compact square shape is the correct fit. The location dictates the winner here.
wattage
Thermomate uses a 1.44 kW electric element at 120 volts. It draws 12 amps of nominal current. Suburban also features an optional electric element with 1,440 watts of input. Both units share the same electric heating power rating. This means their electric heating speed is comparable. However, Suburban adds a 12,000 BTU gas burner. This allows much faster heating when using propane. For electric-only comparison, it is a tie. With gas added, Suburban heats faster overall.
build quality
Thermomate uses a glass-lined tank for insulation and durability. It includes a temperature and pressure relief valve. It is UL Listed for safety. Suburban uses a porcelain-lined steel tank with a replaceable anode rod. This anode rod also serves as a drain, simplifying maintenance. Suburban’s design mimics residential tank longevity. The replaceable anode is a key maintenance advantage for long-term RV use. Thermomate’s glass lining is standard for home units. Suburban’s maintenance features give it an edge for longevity in mobile environments.
temperature control
Thermomate offers an adjustable thermostat with three settings. You can select temperatures from 50°F to 149°F. It also includes a freeze mode to prevent damage in cold climates. Suburban does not list specific adjustable temperature ranges in the provided data. It focuses on recovery rates and heat transfer efficiency. Thermomate gives you direct control over the output temperature. This is useful for preventing scalding at point-of-use sinks. Suburban relies on its heat transfer technology to manage efficiency. Thermomate wins for user-adjustable settings.
Which tankless heater fits your needs
Homeowners needing under-sink hot water
The Thermomate unit plugs directly into a standard 120V outlet. Its 1.44 kW electric heating element provides instant hot water for point-of-use tasks. The adjustable thermostat ranges from 50°F to 149°F, allowing precise temperature control. Its compact 17.7-inch footprint fits easily under most residential sinks without requiring gas lines or complex venting.
RV owners needing versatile power sources
The Suburban heater supports both gas and electric heating. This dual-fuel capability allows you to switch between campsite electricity and onboard propane. The gas mode delivers a recovery rate of 10.1 gallons per hour, while the electric option provides 6.1 gallons per hour. The porcelain-lined steel tank and replaceable anode rod ensure durability in mobile environments.
Users prioritizing corrosion resistance and maintenance
Suburban includes a replaceable anode rod that doubles as a drain, simplifying maintenance. The porcelain-lined steel tank offers enhanced protection against corrosion, mimicking residential water heater longevity. This design helps extend the unit's lifespan in varying water conditions. The durable construction is specifically engineered to withstand the rigors of RV travel and fluctuating power sources.
The products compared
Thermomate 6.5-Gallon Under-Sink Electric Mini-Tank
Best for: Single sink point-of-use hot water
- 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
This Thermomate unit is a 6.5-gallon electric mini tank designed for under-sink point-of-use installation. It operates on a standard 120V outlet with a 1.44 kW heating element. The glass-lined tank offers up to 99% thermal efficiency. You can adjust the temperature between 50°F and 149°F using three settings. Its compact 17.7-inch square footprint allows for wall or floor mounting. This heater suits small kitchens or bathrooms needing instant hot water.
Pros
- 6.5-gallon capacity provides instant hot water
- 120V plug-in connection for easy installation
- Adjustable thermostat from 50°F to 149°F
- UL Listed for safety and durability
- Glass-lined tank for insulation and longevity
Cons
- Limited to 120V electrical requirement
- Only 1.44 kW heating power
- Single tank warranty is 3 years
Good fit if
- You need hot water for a single sink
- You have a standard 120V outlet nearby
- You want a compact under-sink heater
Skip if
- You require high-volume hot water for multiple fixtures
- You only have 240V electrical circuits available
- You need a tankless unit for unlimited supply
Verdict: Thermomate 6.5-Gallon Electric Mini Tank delivers reliable point-of-use heating for small spaces. It fits users who prioritize easy 120V installation and compact dimensions over high-volume capacity.
Suburban 6-Gallon Gas and Electric RV Water Heater
Best for: RV owners 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 RV water heater using Direct Spark Ignition and an electric element. It features a porcelain-lined steel tank with a replaceable anode rod for corrosion protection. The unit measures 12.7 by 12.7 by 19.19 inches and weighs 32.9 pounds. It delivers 10.1 gallons per hour on gas and 6.1 on electric power. This model suits RV owners needing reliable hot water with flexible fuel options.
Pros
- Porcelain-lined steel tank for durability
- Replaceable anode rod for corrosion protection
- Dual fuel capability with gas and electric elements
- Efficient heat transfer via exclusive flue tube design
Cons
- Smaller 6-gallon capacity compared to larger residential units
- Shorter 2-year limited warranty on parts
- Requires specific 12.75 by 12.75 inch cutout dimensions
Good fit if
- You need a compact water heater for an RV
- You want to switch between propane and electric power
- You prioritize tank durability and easy maintenance
Skip if
- You require high-volume hot water for a full house
- You need a unit with a longer warranty period
- You cannot accommodate the specific cutout dimensions
Verdict: Suburban SW6DE 6-Gallon RV Water Heater provides essential hot water for RV living with durable construction and flexible power options. It fits RV owners who value tank longevity and dual-fuel versatility over high capacity.
Specifications side by side
| Spec | Thermomate 6.5-Gallon Under-Sink Electric Mini-Tank | Suburban 6-Gallon Gas and Electric RV Water Heater |
|---|---|---|
| Fuel Type | Electric | Electric, Gas |
| BTU | not stated | 12,000 BTU/h |
| Wattage | 1.44 kW | 1,440 W |
| Capacity | 6.5 Gallons | 6 Gallon |
| Voltage | 120V | not stated |
| Temperature Control | 50°F to 149°F | not stated |
| Certification | UL Listed | not stated |
| Dimensions | 17.7"H x 17.7"W x 14.6"D | 12.69 x 12.69 x 19.19 in |
| Use | Under Sink | RV |
| Weight | 26.5 pounds | 32.9 pounds |
| Size | 6.5 Gallon | 6 Gallon |
| Color | white,blue | Steel |
| Model | ES700 | 5239A |
Frequently asked questions
Can I install the Thermomate mini-tank myself?
Yes, the Thermomate unit is designed for straightforward 120V installation. You connect it to a standard electrical outlet, which makes it accessible for homeowners who want a simple plug-in solution without complex wiring. Its compact dimensions of 14.6 by 17.7 inches also allow it to fit easily under most sinks, simplifying the physical placement process for point-of-use hot water.
Is the Suburban heater suitable for permanent home use?
No, the Suburban model is specifically engineered for RV applications. Its design prioritizes durability and dual-fuel versatility for mobile living rather than residential plumbing systems. The unit is rated for use in recreational vehicles, where space is limited and power sources may vary. It is not intended for standard home under-sink installation.
What is the difference in fuel options between these two?
The Thermomate relies exclusively on 120V electricity, providing a consistent power source for residential use. In contrast, the Suburban unit offers dual-fuel capability, supporting both gas and electric operation. This flexibility allows RV owners to choose their preferred energy source depending on availability, whereas the Thermomate is strictly an electric appliance for indoor use.
Which unit is lighter for transport or installation?
The Thermomate is lighter, weighing 26.5 pounds. This makes it easier to handle during installation under a sink. The Suburban unit is heavier at 32.9 pounds, reflecting its construction for RV environments. If you need a lighter unit for easy mounting in a residential setting, the Thermomate is the more manageable option due to its lower mass.
Does the Suburban heater have a large storage capacity?
No, the Suburban unit provides 4.0 gallons of usable hot water, despite its 6-gallon size rating. This capacity is designed for the compact needs of an RV bathroom or kitchen. It is not intended for high-volume household demands. The storage volume is limited to ensure the unit fits within the tight spatial constraints typical of recreational vehicles.
Can I use the Thermomate for an entire house?
No, the Thermomate is a point-of-use unit designed for a single sink. Its 6.5-gallon capacity and 1.44 kW heating element are insufficient for whole-house hot water needs. It is best suited for small spaces where you need immediate hot water at one specific location, such as a bathroom or kitchen sink, rather than serving multiple fixtures simultaneously.
What are the physical dimensions of the Thermomate unit?
The Thermomate measures 14.6 inches in width, 17.7 inches in length, and 21.2 inches in height. These compact dimensions allow it to fit under most standard sinks. The white or blue exterior helps it blend into residential cabinetry. Its small footprint ensures it does not take up excessive storage space in your kitchen or bathroom.
Is the Suburban heater compatible with standard home plumbing?
It is not recommended for standard home plumbing. The Suburban unit is built for RV systems, which may have different pressure and connection standards. Its dual-fuel design caters to mobile living conditions. For residential under-sink applications, the Thermomate’s 120V electric connection is the appropriate choice for compatibility with typical household electrical and plumbing setups.