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Choosing the right smart water heater affects daily comfort, monthly energy use, and long-term operating cost. A properly selected unit gives you reliable hot water, better temperature control, and opportunities to reduce energy waste through scheduling and remote management. This guide shortlists the top smart water heaters across common capacity and installation needs and explains the technical and practical differences that matter. Below you will find our top picks for multiple home scenarios and the evaluation criteria we used to select them. Use these notes to match a unit to your household size, plumbing setup, and efficiency goals.
Top Picks at a Glance
| Best Quality Built to a higher standard if you want something more solid | Rinnai RX199iN 11.1 GPM Tankless Water Heater |  |
| Best Value The sweet spot between price and what you get | Westinghouse 24kW Tankless Water Heater |  |
| Best Budget The cheapest option that still gets the job done reliably | Westinghouse 14kW Tankless Water Heater |  |
| Top Rated A top-rated pick with lots of positive feedback | Electrolux Infinite 14 Tankless Water Heater |  |
| Most Popular A crowd favorite that many people choose with confidence | WINTEMP 27kW Tankless Water Heater |  |
Rinnai RX199iN 11.1 GPM Tankless Water Heater
| Power Source | Gas Powered |
|---|---|
| Flow Rate | 11 gpm |
| Maximum Temperature | 140 °F |
| Efficiency | UEF 0.98 |
| Mount Type | Wall |
The Rinnai RX199iN is a condensing tankless water heater designed to deliver continuous hot water for larger households and performance-focused buyers. It supports natural gas or propane via a convertible Smart Sense gas control, and the Versa Vent option allows indoor or outdoor installation. The unit claims up to 11.1 gallons per minute, enough to run multiple fixtures at once, and its UEF 0.98 efficiency maximizes energy savings compared with conventional tanks. Practical features include an easy interface, Quick Flush for simpler maintenance, and Wi‑Fi capability through an optional Control‑R module for remote diagnostics and setup. Installation requires a qualified technician and the RX‑OVC vent cap for outdoor installs, and the compact, suitcase-sized footprint helps save space. Trade-offs are that smart features need a separate module, and professional installation plus venting adaptations add to the upfront cost and complexity compared with simpler non-condensing units.
Best for: Homeowners who prioritize continuous high-flow hot water and low operating costs and who are comfortable investing in a professional installation and optional smart accessories to maximize performance.
Less Ideal for: Buyers seeking the lowest initial purchase and installation complexity or those who want smart features included out of the box without extra modules should consider simpler non-condensing or integrated models.
- High runoff performance up to 11.1 GPM suitable for multiple simultaneous fixtures
- Very high energy efficiency (UEF 0.98) reduces fuel consumption
- Convertible fuel design supports natural gas or propane for installation flexibility
- Compact wall-mounted footprint saves space compared with tank heaters
- Quick Flush and Smart Sense controls simplify maintenance and combustion management
- Wi‑Fi remote control requires a separately sold Control‑R module
- Requires professional installation and specific venting parts for outdoor use
Verdict: Choose the Rinnai RX199iN when you want high-flow, ultra-efficient on-demand hot water with flexible fuel and installation options for a performance-focused home.
Westinghouse 24kW Tankless Water Heater
| Wattage | 24 KW |
|---|---|
| Voltage | 240 volts_of_alternating_current |
| Flow Rate | 5.6 gpm |
| Maximum Temperature | 140 °F |
| Mount Type | Wall |
This Westinghouse 24 kW electric tankless water heater is built for steady whole‑house hot water on demand. It uses copper heating elements and self‑modulating electronics to deliver up to 5.6 GPM while keeping temperature stable within about 1°F, which makes it suitable for running several fixtures at once. The unit mounts on the wall and includes a digital LED display plus Wi‑Fi control that works with Alexa and Google Assistant for remote temperature adjustments. Westinghouse ships a plug‑in external scale inhibitor and claims ETL safety protections against overheating, dry‑fire, and leaks, which helps longevity in harder water areas. The practical payoff is reduced standby loss and lower energy use versus a tank heater thanks to self‑modulation. The main practical considerations are the high electrical demand — this model draws large amperage and needs professional hardwired installation — and the physical requirement for compatible electrical service in your home. For buyers who can meet the installation requirements, it provides precise, efficient on‑demand hot water with smart control.
Best for: Homeowners looking to replace a tank system with a smart, efficient on‑demand heater and who prioritize steady multi‑fixture hot water and remote control.
Less Ideal for: People without adequate electrical service or those who want a simple low‑power point‑of‑use heater without major installation work.
- High output (24 kW) and up to 5.6 GPM supports multiple fixtures simultaneously
- Copper heating elements for faster heat transfer and improved durability
- Self‑modulating control that maintains ±1°F temperature stability and improves efficiency
- Built‑in Wi‑Fi with app control and Alexa/Google Assistant compatibility
- Includes external scale inhibitor and ETL safety protections
- Requires substantial electrical capacity and professional hardwired installation
- High amperage draw may need panel upgrades in many homes
Verdict: A powerful, smart tankless heater that delivers steady multi‑fixture hot water and app control for buyers who can support its high electrical requirements.
Westinghouse 14kW Tankless Water Heater
| Kilowatt (Max.) | 14 kW |
|---|---|
| GPM (Max.) | up to 3.4 |
| Power Source | 240V Electric |
| Water Connections | 1/2" NPT |
This Westinghouse 14 kW tankless heater delivers on-demand hot water quickly and fits into small spaces thanks to its slim wall-mount design. It is intended for point-of-use applications such as a single shower plus a faucet, producing up to 3.4 GPM when inlet conditions are favorable and reaching set temperatures in a few seconds. Built-in WiFi with Alexa and Google Home support and a temperature memory function make it easy to monitor and restore settings after power interruptions. Safety and reliability are emphasized with ETL certification, IPX4 moisture protection, a separated water-electricity pathway, and four-layer protection against common electrical and thermal faults. Installation requires a dedicated 60 A double-pole breaker and 6 AWG wire at 240 V, so expect higher initial electrical work compared with small plug-in units. Routine maintenance is straightforward with a removable inlet filter and rotor to limit scale. For buyers who want smart features and compact on-demand hot water without a large footprint, this unit provides a practical balance of performance and safety, provided your electrical service can support it.
Best for: Value-minded buyers who want a smart, space-saving tankless heater for single-shower or point-of-use needs and prioritize app/voice control and safety features.
Less Ideal for: Homes without sufficient 240 V electrical capacity or buyers needing whole-house high-flow hot water should consider higher-capacity options instead.
- Smart WiFi and voice control compatible with Alexa and Google Home for remote temperature adjustment
- Compact wall-mount design saves floor space and fits tight installation locations
- Quick heat-up and up to 3.4 GPM flow suitable for one to two nearby fixtures
- ETL certified with multiple safety protections and IPX4 moisture resistance
- Requires a dedicated 60 A breaker and 6 AWG wiring, increasing installation cost and complexity
Verdict: A compact, smart-enabled 14 kW tankless heater that delivers reliable point-of-use hot water with strong safety features for budget-conscious buyers who can meet its electrical requirements.
Electrolux Infinite 14 Tankless Water Heater
| Wattage | 14 KW |
|---|---|
| Voltage | 240 volts |
| Flow Rate | 3.4 gpm |
| Maximum Temperature | 140 °F |
| Mount Type | Wall |
The Electrolux Infinite 14 is a compact, wall-mounted electric tankless heater built to deliver near-instant hot water to one or two fixtures. It uses 14 kW of power at 240V to produce up to 3.4 GPM, heats water to user-set temperatures between 80°F and 140°F in roughly three seconds, and can be monitored and adjusted over Wi‑Fi or with Alexa voice commands. Self-modulating controls aim to keep temperature steady while improving efficiency, and a factory-included scale inhibitor plus copper heating elements reduce limescale buildup for longer service life. Its slim footprint makes it easy to install in tight spaces but it does require a dedicated 240V/60A two-pole breaker and 6 AWG wiring, so professional electrical work is typically needed. Safety features include overheat and dry-fire protection and ETL certification. The smart controls and scale management make this a good pick for buyers who want a reliable, connected point-of-use solution, though it is not intended to supply whole-house high-flow demands without upgrading electrical service.
Best for: Buyers who prioritize reliable, on-demand hot water and want smart remote control for a point-of-use installation will appreciate this unit.
Less Ideal for: Homes needing high-flow whole-house hot water or those unable to accommodate the required electrical upgrade should look elsewhere.
- Fast instant heating with about 3 second heat-up time
- Built-in Wi‑Fi and Alexa support for remote temperature control and monitoring
- Included scale inhibitor and copper heating reduce limescale and improve durability
- Compact wall-mounted design saves floor space and fits tight locations
- ETL-certified safety features including overheat and dry-fire protection
- Requires a dedicated 240V/60A circuit and heavy-gauge wiring which may need professional installation
- Maximum flow rate (3.4 GPM) limits use to 1–2 fixtures simultaneously
Verdict: A compact, smart 14 kW point-of-use tankless heater that delivers fast, efficient hot water with built-in scale protection for buyers focused on reliable performance.
WINTEMP 27kW Tankless Water Heater
| Wattage | 27000 watts |
|---|---|
| Voltage | 240 volts |
| Flow Rate | 6.5 gpm |
| Maximum Temperature | 140 °F |
| Mount Type | Wall |
The WINTEMP WN27 is a wall‑mounted electric tankless heater designed to deliver continuous hot water for residential use without a storage tank. It uses self‑modulating control to adjust power to incoming water temperature and flow, which helps maintain stable outlet temperatures up to 140°F and reduces wasted energy when demand is low. Installation requires substantial electrical capacity (3 × 40 A breakers and heavy gauge wiring) and a 240V supply, so it is typically fitted by a qualified electrician; once installed the unit supports multiple safety features including overheat, leakage, and dry‑fire protection and is ETL certified. The built‑in LED display and Wi‑Fi remote control make set up and temperature adjustments convenient from a phone. Practical benefits include space savings versus a tank, near‑instant hot water for showers and everyday fixtures, and improved energy efficiency because the unit draws power only when water flows. Limitations are the high electrical demand and the fact that its maximum 6.5 GPM output may not support several simultaneous high‑flow appliances in very cold incoming water conditions.
Best for: Buyers who prioritize reliable, energy‑efficient on‑demand hot water and want a compact, smart‑enabled replacement for a tank heater while valuing verified safety features and practical performance evidence.
Less Ideal for: Households without ample electrical service or those needing very high simultaneous hot water flow for large homes in cold climates should consider higher‑capacity solutions or gas models.
- High 27 kW heat output supports whole‑house use in mild to moderate climates
- Self‑modulating control for stable temperature and efficient energy use
- Wi‑Fi remote control and LED display for convenient temperature adjustments
- Multiple built‑in safety protections and ETL certification
- Compact wall‑mounted design saves space compared with tank heaters
- Requires significant electrical capacity and professional installation
- Maximum flow of 6.5 GPM may be limiting with many simultaneous high‑flow fixtures
Verdict: A powerful, Wi‑Fi enabled electric tankless heater that delivers efficient, on‑demand hot water with strong safety features for buyers who can meet its electrical requirements.
Choosing the Right Smart Water Heater: Key Factors to Consider
Fuel Type and Home Compatibility
The heater's fuel source determines installation complexity and operating cost. Electric, gas, or hybrid designs each have different venting, electrical, and space needs. Before choosing, verify whether your home has the required circuit capacity or gas line and appropriate venting for combustion units.
Fuel selection also affects runtime behavior and efficiency. Electric tanks and heat-pump hybrids often offer simpler installation in homes without gas service, while gas-fired models can provide faster recovery but require safe venting and combustion clearance. Matching fuel type to your existing infrastructure reduces upfront modification costs and minimizes surprises at installation.
Capacity and Recovery Rate
Capacity determines how much stored hot water is available at once, while recovery rate measures how quickly the unit reheats fresh water. For households with multiple simultaneous uses, a higher recovery rate can prevent cold-water interruptions.
Estimate peak hot-water usage by counting simultaneous fixtures and typical shower lengths. Larger tanks or higher recovery ratings suit families with overlapping demand, whereas smaller households may prioritize efficiency over oversized capacity. Consider off-peak heating schedules if your utility offers lower night rates.
Connectivity, Controls, and Scheduling
Smart features let you schedule heating, monitor consumption, and adjust temperature remotely. Controls that offer precise scheduling, vacation modes, and learning algorithms can lower energy use by avoiding unnecessary heating.
Also check whether the app supports multiple user accounts, push alerts for faults, and integration with other smart-home platforms. Reliable firmware updates and a clear privacy policy matter because connectivity introduces ongoing software and security considerations.
Efficiency Ratings and Standby Loss
Look for published efficiency metrics such as Uniform Energy Factor (UEF) for tanks and energy factor figures for tankless or hybrid units. These ratings reflect how much of the input energy becomes usable hot water and help predict operating costs.
Insulation and standby loss determine how much heat the tank loses when not in use. Better insulation reduces repeated reheating and is particularly important for homes with intermittent hot-water schedules or long pipe runs.
Installation Requirements and Placement
Smart water heaters may require network access near the installation location, separate venting, or higher electrical service. Evaluate available space, access for maintenance, and local code requirements before buying.
Placement affects heat loss and pipe run length. Installing the heater closer to frequent-use bathrooms or a kitchen reduces wait time and lowers waste. Ensure there is sufficient clearance for servicing and consider anti-freeze protection if installed in unconditioned spaces.
Warranty, Maintenance, and Serviceability
Warranty length and what it covers indicate expected lifespan and manufacturer confidence. Pay attention to coverage for the tank, control electronics, and heat exchanger separately.
Serviceability influences long-term ownership costs. Choose units with accessible replaceable parts, clear indicators for common faults, and documented maintenance tasks such as anode replacement or sediment flushing. Availability of customer support and documented troubleshooting steps reduce downtime if issues arise.
Sizing a Smart Water Heater for Your Household
Sizing is a balance between stored volume and how quickly the unit recovers. To estimate needs, list typical simultaneous uses during peak morning or evening windows and consult recovery-rate guidance when available. A household with multiple showers running at once needs a larger stored volume or a unit with a higher recovery rate.
If your utility offers time-of-use rates, consider scheduling bulk heating during low-cost periods and using insulated pipe runs to preserve heat. For smaller households, prioritizing efficiency and smart scheduling often makes more sense than oversizing the tank.
- Calculate peak hour demand by adding expected gallons per use
- Match recovery rate to peak demand if simultaneous use is common
- Consider tank size plus scheduled preheating for efficiency gains
Smart Controls: What Works Best in Daily Use
Look for interfaces that make scheduling intuitive and provide clear feedback on current temperature and recent energy use. Controls that support multiple schedule profiles or geofencing allow automatic adjustments for workdays versus vacations.
Push alerts for leaks, performance anomalies, and required maintenance save hassle. An accessible log of historical consumption helps you evaluate whether settings are achieving the expected savings.
- Prefer apps with multi-user support and clear scheduling
- Check for fault alerts and usage history in the control interface
- Evaluate whether voice or hub integration is necessary for your setup
Installation Tips to Minimize Problems
Plan for required clearances, electrical capacity, and network access before selecting a unit. Confirm local codes for venting and pressure-relief installations if the unit is gas-fired. For electric and hybrid models, verify breaker sizing and conduit requirements.
Have a plan for condensate and drainage where applicable, and consider installing a water-softening or sediment-filtering pre-treatment if your area has hard water. This can extend service life and reduce maintenance frequency.
- Pre-check electrical and gas supply capability
- Reserve space for servicing and an accessible pressure-relief valve
- Address water quality to protect internal components
Maintaining Efficiency Over Time
Regular maintenance keeps a smart water heater operating near its rated efficiency. Tasks include flushing sediment, inspecting the anode rod, and reviewing app-reported alerts. Scheduling these tasks annually or per the manual reduces the chance of lost capacity and premature failure.
Firmware updates for connected controllers can add features and security patches. Plan for occasional software maintenance the same way you would software on other smart-home devices to avoid unexpected behavior.
- Flush tank and check anode annually or as recommended
- Monitor app alerts and apply firmware updates promptly
- Keep reachable log of service dates and parts replaced
Energy-Saving Strategies With a Smart Heater
Use scheduled setbacks during long absences and lower standby temperatures when hot-water demand is low. Some smart heaters offer adaptive learning that reduces heating during predictable low-use windows without losing morning comfort.
Combine tank insulation, pipe insulation, and demand-focused schedules to minimize repeated recovery cycles. Tracking usage patterns in the app helps refine schedules and quantify savings over time.
- Implement vacation and low-use schedules
- Insulate tank and hot-water lines to reduce standby loss
- Use usage data to optimize heating windows
How We Chose the Best Smart Water Heater
We focused on technical features and real-world usability that determine long-term satisfaction with a smart water heater. Key evaluation criteria included energy efficiency and thermostat control, because reduced standby loss and precise temperature management have the biggest impact on operating cost and comfort. Connectivity and app controls were assessed for stability, scheduling flexibility, and integration with smart home systems. Installation and compatibility covered required venting, fuel type, and whether typical residential plumbing and electrical setups accommodate the unit. Recovery rate and capacity were evaluated to ensure the heater can meet peak demand for families of different sizes. Durability and warranty depth were also part of the selection process to reflect lifecycle value. We excluded specialty commercial units, products lacking documented efficiency specs, and models without basic remote-control capabilities. Our shortlist favors units with clear spec sheets, demonstrable energy-saving modes, and practical installation requirements that fit most homes.
Our full evaluation process is outlined in our review methodology.
FAQ
How do I know what tank size I need for my household?
Estimate peak hour demand by adding the gallons used during the busiest hour, including simultaneous showers and appliance use. Match that number to manufacturer capacity and consider recovery rate for rapid reheating needs.
Are smart features worth it if I only have one bathroom?
Often yes. Even in small households, scheduling, remote temperature control, and energy usage feedback can reduce wasted heating and let you preheat water only when needed, lowering operating costs.
Will a smart water heater work without a reliable Wi-Fi network?
Basic heating functions typically work without Wi-Fi, but smart scheduling, remote control, and firmware updates require network access. Consider a unit with local controls that allow manual scheduling if connectivity is unreliable.
What maintenance tasks are most important for longevity?
Flushing sediment, inspecting and replacing the anode rod when needed, and monitoring for leaks are key. Address app alerts promptly and follow the maintenance intervals recommended in the manual.
Can I use smart schedules to save on off-peak electricity rates?
Yes. Many smart units support time-of-use scheduling so you can heat during lower-rate periods. Pair scheduling with sufficient tank capacity to cover peak-demand windows.
Final Verdict
Choosing a smart water heater comes down to matching capacity and recovery to your household demand while prioritizing efficient operation and reliable controls. Focus on fuel compatibility and installation constraints first, then evaluate connectivity features, published efficiency ratings, and serviceability. Prioritize units that fit your existing electrical or gas infrastructure and offer clear scheduling and alerting to realize energy savings. With those tradeoffs in mind, you can pick a smart water heater that balances comfort, convenience, and lower operating costs.