Choosing an electric tankless water heater for a family means matching the unit to your home’s electrical capacity and the number of hot-water fixtures you may use at once. A larger kilowatt rating can support more demand, but incoming water temperature and flow needs matter too. The five options below range from compact, lower-output models to higher-capacity units intended for multiple fixtures.
Table of Contents
Quick Comparison
| Product | Power | Published flow rate | Electrical requirements to note | Best suited for |
|---|---|---|---|---|
| Vancepic 27kW Electric Tankless Water Heater | 27 kW, 240V | Not specified | Three 40A breakers | Homes with several hot-water use points |
| Rheem RTEX-24 | 24 kW, 240V | Up to 5.9 GPM | Three 40A double-pole breakers; 200A service recommended | Higher-demand homes with suitable electrical service |
| Rheem RTEX-11 | 11 kW, 240V | Up to 2.68 GPM | One 50A double-pole breaker; 100A service recommended | One or a limited number of fixtures |
| 14kW Westinghouse / APOLO-listed model | 14 kW, 240V | Up to 3.38 GPM | One 60A double-pole breaker; #6 AWG wire specified | Small homes or limited simultaneous use |
| Stiebel Eltron Tempra 20 Trend | 19.2 kW, 240V | 2.01 GPM listed | At least 125A electrical service recommended | Homes seeking a compact, mid-range unit |
Our Picks: Best Electric Tankless Water Heaters For Family Of reviews
1. Vancepic 27kW: A High-Output Option for Multiple Use Points
The Vancepic is the highest-output unit in this group at 27 kW. Its listing describes it as suitable for two to four use points around the home, which makes it one of the more promising choices here for families that may need hot water in more than one place. The actual flow you get depends on conditions such as incoming water temperature and how many fixtures are running, so treat that use-point guidance as a starting point rather than a guarantee.
The wall-mounted unit measures 13.8 by 18.7 inches and is just over three inches deep. It has knob controls and an LED display, with temperature settings from 86°F to 131°F. The product information also lists leakage and overheat protection and automatic shutoff. Its heating elements are described as separated from the water to help limit scale buildup.
The key trade-off is the electrical demand: the manufacturer specifies 240V power and three 40A breakers. Check your panel and wiring before buying, and have a qualified electrician confirm the installation requirements. The listing does not give a flow-rate figure, making direct capacity comparisons harder than with the Rheem options.
Pros:
- Highest wattage among the models in this comparison.
- Designed for multiple hot-water use points.
- LED display and one-degree temperature adjustments.
- Compact wall-mounted design with listed safety protections.
Cons:
- Requires three 40A breakers, so electrical capacity may be a limiting factor.
- No published GPM figure is provided in the supplied product details.
Verdict: Consider the Vancepic if you need a high-output unit for several use points and your electrical system can support its demanding installation requirements.
2. Rheem RTEX-24: A High-Capacity Model With a Stated Flow Rate
The Rheem RTEX-24 delivers 24 kW at 240V, and its listing gives a maximum flow rate of up to 5.9 GPM. That number makes it easier to compare with other models, but it is not a promise of that flow in every home or at every temperature rise. Your local incoming-water temperature and the number of fixtures drawing hot water affect what the unit can deliver.
Its digital thermostat adjusts in one-degree increments from 80°F to 140°F. The compact wall-mounted design needs no venting, and the product information says it requires three 40A double-pole breakers, three sets of #8 AWG copper conductors with ground, and recommends a minimum 200A household service panel. Those requirements make an electrical assessment essential before purchase.
Compared with the 27 kW Vancepic, the RTEX-24 has slightly less rated power but provides a stated maximum GPM. It also comes from an established water-heater brand. The supplied product information includes different warranty descriptions, so check the current warranty terms for the exact model before deciding.
Pros:
- Published maximum flow rate of up to 5.9 GPM.
- Temperature control in one-degree increments.
- Compact design with no venting requirement.
- Higher output than the 11 kW Rheem model in this comparison.
Cons:
- Requires three 40A double-pole breakers and substantial wiring.
- The recommended 200A service may rule it out for some homes without electrical upgrades.
Verdict: The RTEX-24 is a strong candidate for a family needing a higher-output unit with a published flow figure, provided the home meets its electrical requirements.
3. Rheem RTEX-11: A Smaller Choice for Limited Hot-Water Demand
The Rheem RTEX-11 is an 11 kW, 240V model with a published maximum flow rate of up to 2.68 GPM. Its lower output means it is better suited to a limited hot-water load than to a home where several showers and taps may run at once. It could be a fit for a small household, a secondary space, or a specific group of fixtures, depending on your actual demand.
The temperature control adjusts in one-degree steps from 80°F to 140°F. At 8.25 inches wide and 12.63 inches tall, it is notably compact. Rheem specifies a 50A double-pole breaker and #8 AWG copper conductors with ground, and recommends at least 100A household electrical service.
Compared with the 24 kW RTEX-24, this model has a lower electrical and hot-water capacity. That can make it more practical where demand is modest, but it is not the right choice simply because it is smaller or less powerful. Be sure its output matches the fixtures you intend to use together.
Pros:
- Compact dimensions suit installations with limited wall space.
- Published maximum flow rate of up to 2.68 GPM.
- One-degree temperature adjustment from 80°F to 140°F.
- Lower output than the larger whole-home options in this list.
Cons:
- Its listed flow rate may be too limited for several high-demand fixtures at once.
- Still requires a dedicated 50A double-pole breaker and suitable service capacity.
Verdict: Choose the RTEX-11 for a smaller or carefully limited hot-water load, not as a default whole-home choice for a busy family.
4. 14kW Westinghouse / APOLO-Listed Model: Compact With Smart Controls
This 14 kW, 240V model is listed with a maximum flow rate of 3.38 GPM and a starting flow rate of 0.5 GPM. The product description presents it as suitable for two points of use, such as a shower and sink. As with any electric tankless heater, the maximum flow figure does not tell the whole story: performance depends on water temperature and how much hot water those fixtures need.
Features include Wi-Fi control, app-based temperature adjustments, and compatibility with Alexa and Google Home. The unit is compact, with a wall-mounted design, 1/2-inch NPT connections, and listed protections against leakage, overheating, dry firing, and high voltage. Its specified electrical setup is one 60A double-pole breaker and #6 AWG wire.
There is an important listing detail to check before ordering: the product title is generic, while the supplied description refers to APOLO and identifies Westinghouse as the brand. Confirm the exact manufacturer, model, certifications, and installation instructions on the product page. Its output sits between the 11 kW Rheem and the larger whole-home options, making it a possible fit for limited simultaneous use rather than the heaviest family demand.
Pros:
- Published maximum flow rate of up to 3.38 GPM.
- Wi-Fi and voice-assistant features for remote control.
- Compact wall-mounted design.
- Product description lists several protective features and ETL certification.
Cons:
- Requires a 60A double-pole breaker and #6 AWG wire.
- The brand and model naming differs across the supplied listing details, so verify the exact product before purchase.
Verdict: Consider this model if you want smart controls and its stated two-point capacity suits your needs, but confirm the listing identity and electrical requirements first.
5. Stiebel Eltron Tempra 20 Trend: A Mid-Range Unit With a Quiet-Operation Focus
The Tempra 20 Trend is rated at 19.2 kW and 240V. Its listed flow rate is 2.01 GPM, so compare that figure carefully with your household’s likely simultaneous demand before treating it as a whole-home solution. The product description emphasizes continuous on-demand operation and automatic modulation, which adjusts the unit’s output to the hot-water need.
The unit has a digital temperature display and a compact design measuring 16.63 by 14.5 inches. Its stated temperature range is 68°F to 140°F. The product details recommend at least 125A electrical service; the listing also notes two 40A breakers and an 80A draw. Ask an electrician to confirm the correct wiring and panel requirements for your home and the exact model.
Compared with the Rheem RTEX-24, the Stiebel Eltron has lower listed output and a much lower published GPM figure. Its product information also highlights quiet operation and includes leakage and parts warranty terms. It may suit a household with moderate demand, but the flow specification makes careful sizing especially important.
Pros:
- Automatic modulation is designed to match output to hot-water demand.
- Compact wall-mounted design with no venting requirement.
- Digital temperature display and a broad stated temperature range.
- Product information describes quiet operation and lists warranty coverage.
Cons:
- The listed 2.01 GPM may not support high simultaneous demand.
- Electrical service and breaker requirements need careful review before installation.
Verdict: The Tempra 20 Trend is worth considering for moderate demand and a compact installation, but families with frequent overlapping hot-water use should compare its listed flow closely with their needs.
How to Choose an Electric Tankless Water Heater for Your Family
Estimate How Many Fixtures May Run at Once
Think about your busiest moments, not just the number of people in your home. For example, a shower running while someone uses a sink creates more demand than one fixture alone. Make a list of the fixtures you expect to use at the same time, then compare that combined need with the heater’s published flow rate and sizing guidance.
Account for Incoming Water Temperature
A heater must raise cold incoming water to your chosen temperature. Colder incoming water can limit how much hot water an electric tankless unit can deliver at once. Published maximum GPM figures are useful for comparison, but they do not guarantee the same output in every location or season. Check the manufacturer’s sizing guidance for your climate and desired temperature.
Check Your Electrical Panel Before You Buy
Electric tankless heaters can require substantial electrical capacity. The products here call for setups ranging from a 50A breaker to multiple 40A breakers, and some list minimum household service recommendations. Ask a qualified electrician to check your panel, wiring, available spaces, and the unit’s exact installation instructions. The cost and feasibility of an electrical upgrade may affect which model makes sense.
Compare Wattage and Flow Rate Together
Wattage helps show how much heating power a unit can provide, while GPM gives a flow-rate reference. Neither figure alone guarantees that a heater will keep up with your family’s use. Some listings provide a maximum GPM while others do not, so use manufacturer sizing charts and your household’s fixture needs to make an apples-to-apples comparison.
Choose a Temperature Range That Fits Your Household
Look at the unit’s temperature range and how its controls work. Several models here offer digital displays and fine temperature adjustments, while the Vancepic uses knob controls with an LED display. Set temperatures according to the manufacturer’s instructions and household needs, and consider whether simple controls or app-based access matters to you.
Review Connections, Space, and Installation Details
Measure the available wall space and check the water connection size before ordering. The products vary in dimensions and connection details, and they may require different wiring and breakers. Have a qualified installer confirm that the unit can be mounted and connected correctly. Do not assume that compact size means a simple electrical installation.
Verify the Exact Model, Certifications, and Warranty
Read the complete listing and installation manual for the exact model you plan to buy. This is especially important when the product title and description use different brand or model names. Confirm any claimed safety certification, the included components, and warranty terms directly with the manufacturer or seller before purchase.
Frequently Asked Questions
Can an electric tankless water heater supply hot water to a whole house?
It can, if the unit is correctly sized for the home’s peak flow needs and the electrical system can support it. A product labeled for whole-house use is not automatically suitable for every household. Compare fixture demand, local incoming water temperature, and the manufacturer’s sizing guidance.
How many showers can these heaters run at the same time?
There is no single answer based on the product name or wattage alone. The number depends on the heater’s output, the water temperature rise needed, shower flow, and whether other fixtures are also drawing hot water. Use the manufacturer’s flow and sizing information for your conditions.
Will I need to upgrade my electrical panel?
Possibly. These models have significant electrical requirements, and some recommend household service of 100A, 125A, or 200A. An electrician should inspect your existing service and confirm whether it can support the heater and any other major electrical loads.
Does a tankless heater provide unlimited hot water?
It heats water on demand rather than storing a tank of hot water, but its delivery rate is still limited. If the household asks for more hot water than the unit can heat at once, flow or temperature may not meet expectations.
Are the published GPM figures guaranteed in every home?
No. A listed maximum flow rate is a product specification, not a guarantee for every installation. Incoming water temperature, selected output temperature, and simultaneous fixture use can change the flow a unit can deliver.
Which model is the best starting point for a busy family?
The Vancepic 27 kW and Rheem RTEX-24 are the higher-output options in this group. The Rheem has a published maximum flow rate, while the Vancepic has greater rated wattage and is described for multiple use points. Either choice still needs to be checked against your household demand and electrical capacity.
Should I install an electric tankless water heater myself?
Because these units can require high-current circuits and specific wiring, professional installation is the safer approach. Follow the manufacturer’s instructions and local requirements, and have a qualified electrician verify the electrical work.
Final Recommendation
For a family with several potential hot-water demands, start by comparing the Vancepic 27 kW and Rheem RTEX-24, then confirm that your electrical service can support the chosen unit. The RTEX-11 is better suited to limited demand, while the 14 kW model and Stiebel Eltron may fit homes whose simultaneous use stays within their stated capacity. The right choice depends less on family size alone than on your peak fixture use, incoming water temperature, and electrical system.
