Choosing an electric water heater for a tiny house means balancing hot-water needs with limited space and electrical capacity. A compact tank can store hot water for several uses, while a tankless point-of-use unit saves space but may need a dedicated circuit and only serve one sink. The options below range from small 8-gallon tanks to an 18-gallon model, so check the electrical requirements and intended use before choosing.
Table of Contents
Quick Comparison
| Water Heater | Type and Capacity | Power Details | Best Fit |
|---|---|---|---|
| CAMPLUX 10-Gallon Point-of-Use Electric Water Heater | Tank, 10 gallons | 1500W, 120V | A compact tank for several nearby uses |
| GE 18-Gallon Plug-and-Play Electric Water Heater | Tank, 18 gallons | 120V; exact wattage not listed | More stored hot water in a small home |
| ThermoMate 3500W Tankless Electric Water Heater | Tankless, 0.4–0.66 GPM | 3500W, 120V; hardwired | On-demand hot water at a single sink |
| ThermoMate 8-Gallon Point-of-Use Water Heater | Tank, 8 gallons | 1500W, 120V; hardwired installation required | A small tank for a sink or as a booster |
| Ariston Andris Mini-Tank Electric Water Heater | Tank, 8 gallons | 120V; wattage not listed | A compact tank for a single sink |
Our Picks: Best Electric Water Heaters For Tiny House reviews
CAMPLUX 10-Gallon Tank for Small Spaces and Multiple Uses
The CAMPLUX is a small storage-tank heater with a 10-gallon capacity. Its listed dimensions are 14.75 inches wide by 24.5 inches high, making it a possible fit for a utility area, under-counter space, or another spot with enough room for the tank and its connections.
It runs on 1500W at 120V, and the manufacturer says it takes about 60 minutes to heat a full tank. The adjustable thermostat gives you control over the water temperature, while the built-in temperature-and-pressure relief valve provides an important safety feature. The product description also says its insulation can help keep water hot for up to 24 hours.
Compared with the 8-gallon options, this model stores more hot water, which may be useful when you want to serve more than one nearby fixture. Still, 10 gallons is a limited reserve for long showers or several back-to-back uses. Check the installation space and plumbing layout, and confirm the unit’s electrical requirements work with your home.
Pros:
- 10-gallon tank offers more stored water than the 8-gallon choices.
- Uses a 120V, 1500W supply.
- Includes an adjustable thermostat and T&P relief valve.
- Compact dimensions are suited to small-space installations.
Cons:
- The stated full-tank heating time is about 60 minutes.
- Its stored supply may not cover long or closely spaced high-use periods.
Verdict: Choose the CAMPLUX if you want a modest storage tank for a tiny house and can accommodate its size and recovery time.
GE 18-Gallon Heater for a Larger Stored Hot-Water Supply
With an 18-gallon tank, this GE model offers the largest listed storage capacity in this comparison. It can be used for a single hookup or as a hot-water source for a small home, condo, or apartment. In a tiny house, its added capacity may help when a smaller point-of-use tank would run short too quickly.
The heater connects to a 120V supply and uses standard 3/4-inch NPT water connections. GE describes it as a plug-and-play installation with existing plumbing, though you should still verify the electrical setup and installation instructions for your specific home. An adjustable thermostat lets you set the temperature, and the stainless steel heating element and anode rod are intended to help protect the unit against corrosion.
The larger tank takes up more space than the 8- and 10-gallon choices, and the product details do not provide wattage or recovery time. Those missing details make it harder to estimate how quickly it will reheat after heavy use. Treat “whole home flexibility” as a possible use, not a guarantee that the tank will meet every household’s flow and hot-water needs.
Pros:
- Largest listed tank capacity in this group at 18 gallons.
- Can serve as a standalone heater or as a booster.
- Uses 120V power and standard 3/4-inch NPT water connections.
- Includes an adjustable thermostat, stainless steel heating element, and anode rod.
Cons:
- Requires more installation space than the smaller tanks.
- The supplied product details do not state wattage or recovery time.
Verdict: Consider the GE if stored capacity matters more than minimizing the heater’s footprint, and confirm its electrical and hot-water performance suit your setup.
ThermoMate Tankless Heater for On-Demand Sink Hot Water
This compact ThermoMate unit heats water on demand rather than storing it in a tank. At 7.9 by 6.4 by 2.5 inches, it can fit in tight spaces such as beneath a sink. Its listed flow range is 0.4 to 0.66 gallons per minute, so it is best considered for a single sink rather than as a source for multiple fixtures or a high-flow shower.
The heater is rated at 3500W and 120V, draws 29.2 amps, and must be hardwired; it does not have a plug. The manufacturer specifies a 32A double-pole circuit breaker and minimum 10 AWG wire. That electrical demand is a key factor in a tiny house, where available circuit capacity may be limited. The unit has a digital temperature display, adjustable settings from 86°F to 131°F, and self-modulating power that adjusts with changes in water flow and inlet temperature.
Unlike a tank heater, it does not provide a reserve of stored hot water. Its small size can save cabinet space, but the required wiring and low listed flow range make it a specialized choice. Have a qualified professional confirm the circuit and installation before buying.
Pros:
- Very compact design fits under many sinks.
- Heats water on demand without a storage tank.
- Digital controls allow temperature adjustment in 1-degree increments.
- Self-modulating power responds to changes in flow and inlet temperature.
Cons:
- Requires hardwiring, a 32A double-pole breaker, and at least 10 AWG wire.
- Its listed flow range is intended for limited, point-of-use use.
Verdict: Pick this ThermoMate for a single sink only if your electrical system can support its specified dedicated circuit.
ThermoMate 8-Gallon Tank with Adjustable Temperature Control
This 8-gallon point-of-use tank is designed to put hot water close to a sink or to work as a booster in line with a larger water heater. Its listed 20.75-inch low-profile height may make it easier to place in a constrained utility area, though you will need room for the full unit and plumbing connections.
The heater uses a 1500W element at 120V, and its thermostat adjusts from 90°F to 150°F. The manufacturer specifies hardwired installation, with a power cord included for optional installation, so confirm the permitted setup in the installation instructions before planning the electrical connection. The tank has a porcelain enamel glass lining, and the listed safety features include a T&P relief valve, independent drain port, and high-temperature limit protection.
Compared with the 10-gallon CAMPLUX, this model stores less water but offers an explicitly stated low profile and a wide thermostat range. Its 8-gallon capacity is most practical for one nearby fixture or as a booster; it is not a large whole-house reserve.
Pros:
- Compact 20.75-inch low-profile design.
- 1500W, 120V operation and adjustable thermostat.
- Can be installed independently or used as an inline booster.
- Includes a drain port, T&P relief valve, and high-temperature limit protection.
Cons:
- 8-gallon capacity may be limiting for multiple fixtures or extended use.
- Installation requirements need careful checking because hardwiring is specified.
Verdict: Choose this ThermoMate if you need a low-profile 8-gallon tank for a nearby sink or a booster application.
Ariston Andris Mini-Tank for a Single Sink or Remote Spot
The Ariston Andris is an 8-gallon mini-tank intended for a single sink or another remote hot-water location. It can be installed as a standalone unit or used as a booster alongside an existing water-heating system. That flexibility may help in a tiny house where a distant fixture takes time to receive hot water from a central heater.
The product description lists 120V operation and a titanium glass-lined tank, which is intended to support heat retention and durability. It is designed for hardwiring and compact installation, but the supplied details do not state wattage, dimensions, or a recovery time. Those gaps make it important to check the full installation information and confirm that the tank fits your space and electrical plan.
Its capacity is similar to the ThermoMate 8-gallon model, but this product’s listed strengths are its mini-tank format and standalone or booster installation options. It is not the right choice if you need a large supply for several fixtures at once.
Pros:
- 8-gallon tank is sized for a single sink or remote location.
- Can operate as a standalone unit or a booster.
- 120V power and a titanium glass-lined tank are listed.
- Compact design is aimed at small spaces, including RVs and under-sink areas.
Cons:
- Wattage, dimensions, and recovery time are not provided in the product details.
- Its 8-gallon capacity is limited for multiple fixtures or longer use.
Verdict: Consider the Ariston for a single remote sink or booster setup, but verify its fit and electrical specifications before installation.
How to Choose an Electric Water Heater for a Tiny House
Match tank capacity to your routine
Think about how many people will use hot water and whether the heater serves one sink or several fixtures. An 8-gallon mini-tank is aimed at a single sink or booster role, while the 10-gallon CAMPLUX offers a little more stored water. The 18-gallon GE provides the largest reserve in this group, but no small tank guarantees enough water for long showers or several uses in a row.
Decide between a tank and tankless design
A tank heater stores hot water, so it can supply a short burst without heating the water from scratch at the moment you turn on a tap. It also needs space for the tank and time to recover after use. A tankless heater takes up less room and heats water on demand, but the ThermoMate listed here has a limited flow range and is intended for a sink. Choose based on the actual fixture and flow you need, not just the unit’s size.
Check the electrical requirements before buying
Do not assume that every 120V heater can use the same outlet or circuit. The product details list different requirements: the tank models include 1500W options, while the ThermoMate tankless unit requires hardwiring, a 32A double-pole breaker, and minimum 10 AWG wire. Confirm your available electrical capacity and follow the installation instructions. Ask a qualified electrician if you are unsure.
Measure the installation area and plumbing route
Measure the spot where the heater will go, including space needed for water connections, wiring, and access for servicing. Compare those measurements with the product’s listed dimensions; only some options here provide exact measurements. Also check connection sizes and the position of nearby hot-water lines. A compact body can still be difficult to install if there is not enough room around it.
Consider recovery time and how far hot water must travel
For a tank, recovery time affects how soon hot water is available again after heavy use. The CAMPLUX description states about 60 minutes to heat a full 10-gallon tank; recovery details are not given for all the other models. A point-of-use heater can sit near a sink, which may make sense when the fixture is remote from a central heater. Consider the actual layout of your home and verify performance details that matter to your routine.
Review temperature controls and safety features
An adjustable thermostat helps you set the desired water temperature, while a temperature-and-pressure relief valve is an important safety component on tank heaters. Some listings also specify features such as a drain port or high-temperature limit protection. Follow the manufacturer’s instructions for installation and operation, and make sure the safety equipment is properly installed.
Frequently Asked Questions
What size electric water heater works best in a tiny house?
It depends on how many people and fixtures it serves. An 8-gallon tank may work for one sink or as a booster, while a 10- or 18-gallon tank offers more stored water. Estimate your daily use and check the unit’s recovery information before deciding.
Can a small electric water heater supply a shower?
Some of these products are described for uses that include showers, but a small tank has a limited hot-water reserve. The tankless option in this comparison lists a flow range of 0.4 to 0.66 gallons per minute and is specified for sink use. Check the heater’s capacity and flow against your shower’s needs before buying.
Is a tankless heater always the better choice for a tiny house?
No. A tankless unit can save installation space, but it may need a dedicated circuit and can have limits on flow. A small tank takes up more room but stores hot water for use. Compare both the electrical requirements and the amount of hot water your routine needs.
Can I plug a point-of-use water heater into a standard outlet?
Do not assume so. Requirements vary by model. For example, the ThermoMate tankless unit in this comparison must be hardwired and specifies a 32A double-pole breaker and minimum 10 AWG wire. Follow the particular model’s instructions and have an electrician confirm your setup if needed.
Can a mini-tank be used with an existing water heater?
Yes, several products here are described for use as boosters alongside another water heater. Check the model’s connection instructions and confirm that the plumbing arrangement works for your system.
How much installation space should I leave?
Start with the product’s dimensions, then allow space for connections, wiring, and access to the unit. The CAMPLUX listing gives dimensions of 14.75 inches wide by 24.5 inches high, and the ThermoMate 8-gallon tank is listed as 20.75 inches high. Check each model’s full instructions before planning the installation.
Final Recommendation
For a tiny house that needs a compact tank with a little more stored water than an 8-gallon mini-tank, the CAMPLUX 10-gallon model is a practical place to start, provided its dimensions and heating time work for your routine. The GE 18-gallon heater is the option to consider when added storage capacity matters most. For a single sink and a suitable dedicated circuit, the ThermoMate tankless unit offers the smallest listed form factor. In every case, confirm the installation space, plumbing connections, and electrical requirements before you buy.
