Best Smart Water Heaters

Prices in this article are typical U.S. retail, checked November 2026. All assessments are research-based and untested.

Section 1: Which way of heating water fits your house? (Introduction)

The best smart water heater for an all-electric house is the Rheem ProTerra 50-gallon heat pump at $1,699. Gas homes should fit the Navien NPE-240A2 tankless at $1,949, and anyone with a working tank should add the $149 Aquanta controller instead of replacing it.

How we chose: we compared four ways to get app control and better hot water — a heat pump, a whole-house gas tankless unit, a small-home gas tankless unit and a retrofit controller — on fuel, capacity, efficiency, app and price, then matched each to a house. Nothing here was tested hands-on; the assessments come from manufacturer documentation and published efficiency ratings.

The water heater is the appliance nobody looks at until it leaks. It sits in a closet or a garage, heats water around the clock, and quietly takes a bigger share of the energy bill than the refrigerator, the dishwasher and the dryer combined, according to ENERGY STAR. That is why this is one of the few upgrades where the app is the least interesting part.

The mechanics — heat pump versus resistance versus gas, closet air volume, condensate, the electrical panel — are covered in Smart Water Heaters: The Closet Upgrade. This page answers the narrower question: once you know your house can take a new water heater, which one do you buy, and is the connected version worth the money? For the wider device picture, start with the Devices hub.

Section 2: What does the app actually buy you?

A connected water heater is a heater with a radio, not a better heater. The tank, the element, the compressor and the venting decide how much hot water you get and what it costs. The radio adds information and control, and only some of that is worth paying for.

The features that earn their place, in order:

• Leak detection and automatic shutoff. A tank failure is one of the most expensive common home disasters: water on the floor, ruined drywall, a rushed replacement at holiday prices. Rheem’s LeakGuard puts a sensor at the base of the unit and closes the supply when it trips. Aquanta does something similar with an optional sensor, minus the shutoff.
• Schedules and away modes. Heating water at 5 p.m. instead of 3 p.m. matters on a time-of-use rate, and a vacation mode stops an empty house from staying at 130°F for a week. The time-of-use guide covers the tariff side.
• Usage data. A dashboard that shows what the heater cost last month turns an invisible load into a number you can act on. It is also how you find out the unit has been on backup heat all winter.
• Alerts and diagnostics. A dirty filter, a tripped sensor, an error code: better as a notification than as a cold shower.

What the app does not do is just as important. It does not make a resistance tank efficient, it does not add capacity, and it does not survive a dead router. None of the four is sold as a Matter or Apple Home device, and HomeKit is not on the list either, so “smart” here means a manufacturer app plus, on some models, Alexa or Google voice control. If the internet is down, the heater still heats; you just cannot see or change it from the couch.

The ranking is therefore blunt: leak shutoff first, scheduling second, dashboards third. A $149 controller that texts you about a leak is worth more than a $1,699 heat pump whose app you opened once.

Section 3: How do the four options compare?

Rheem ProTerra 50

The ProTerra is the default answer for a house that already has an electric tank. It moves heat from the surrounding air into the water instead of burning a resistive element as the only source, which is why Rheem claims up to four times the efficiency of a standard electric tank and up to 75 percent less energy use. The 50-gallon side-connection model carries a 3.88 UEF, an ENERGY STAR rating, an 87-gallon first-hour delivery and a 10-year limited tank and parts warranty. Top-connection and 30-amp variants reach 4.07 UEF.

The smart part is built in: EcoNet over Wi-Fi, with temperature, vacation mode, energy reports and LeakGuard shutoff from the app. No hub, no subscription.

The trade-offs are physical. ENERGY STAR asks for 1,000 cubic feet of air space and a room that stays between 40°F and 90°F year-round, which rules out a cold garage and a tight closet without a louvered door or ducting. The unit produces condensate that needs a drain or a pump, it cools and dehumidifies the room it sits in, and it needs a dedicated 240-volt circuit. Recovery is slower than a resistance tank of the same size, so the first-hour rating matters more than the gallon count. Buy it if the house is electric, the space has air, and the panel has room. Skip it if gas is cheap or the only spot is a freezing garage.

Navien NPE-240A2

This is the whole-house gas answer. The NPE-240A2 is a condensing tankless unit rated at 199,900 BTU/h, UEF 0.95, and 11.2 gallons per minute at a 35°F rise — about 5.6 GPM once the incoming water is cold enough to need a 70°F rise. ComfortFlow adds a small buffer tank and a recirculation pump inside the case, which shortens the wait for hot water without a separate recirculation line in some layouts. It is 17.3 inches wide, 27.4 tall and 13.2 deep, field-convertible between natural gas and propane, and Navien’s own EnergyGuide-based estimate puts annual gas use at about $195 against $319 for a 50-gallon tank.

The catch is the radio. Wi-Fi is not built in. NaviLink is a separate module that adds remote temperature, usage data and error notifications through Navien’s app. Budget for it, and budget for venting, gas piping and an annual descaling service. A tankless unit also stores no hot water: in a power cut, the burner has nothing to circulate.

Buy it if the house has gas, three or more bathrooms, and someone who will book the yearly flush. Skip it if you want hot water during an outage or you are replacing a tank in a hurry.

Eccotemp SHLX 4.5 GPM

The SHLX is the budget route into a connected gas tankless heater. It is rated at 4.5 GPM at 80,000 BTU and a 35°F rise, which is a one-bathroom-at-a-time unit: fine for a small house, an ADU, a cabin or a couple, not fine for a family filling a tub while the dishwasher runs. The Eccotemp app covers temperature, schedules, timers, eco mode, consumption statistics and error monitoring, and it works with Alexa and Google. The unit is CSA tested for the U.S. and Canada up to 2,000 feet, and the warranty is five years on the heat exchanger and two years on components — shorter than the premium brands.

At $549 on sale ($609 list) it costs a quarter of the Navien and does the same job at a third of the capacity. That is the honest trade: less headroom, a shorter warranty, a smaller service network, and no buffer tank.

Buy it if the demand is modest and the budget is real. Skip it if two showers and a washing machine ever run at once.

Aquanta controller

Aquanta is not a water heater. It is a $149 controller that wires into an existing tank — nearly all electric models and most gas models — and adds Wi-Fi scheduling, remote on/off, hot water level, energy tracking and an overheat shutoff, plus leak alerts through an optional sensor. It learns the household’s pattern and heats around it, and it works with Alexa and IFTTT.

For a tank that is five years old and working, this is the rational purchase. It costs a tenth of the ProTerra, it keeps a perfectly good tank out of the landfill, and it captures the two features people actually use: a schedule and a leak alert. It cannot make the tank more efficient, though. The savings come from heating less often, so they depend on the schedule and the tariff, not on the hardware.

Buy it if the tank has years left and the bill is the complaint. Skip it if the tank is past ten years old: put the $149 toward the replacement instead.

Section 4: How do sizing and wiring decide the install?

Size by first-hour rating and flow rate, not by gallons. A tank’s gallon count is the headline, but the number that decides whether you run out is the first-hour rating on the yellow EnergyGuide label: how much hot water the unit can deliver in an hour of heavy use. A heat pump tank recovers slowly, so a 50-gallon hybrid can underperform a 50-gallon resistance tank in a house with a big tub. For tankless, the number is gallons per minute at your actual temperature rise, and the rise depends on groundwater: a unit rated 4.5 GPM at 35°F delivers roughly half that in a northern winter.

The electrical work is part of the project. A 240-volt heat pump unit needs a dedicated circuit and a panel check. Rheem sells 120-volt plug-in models for houses without a spare 240-volt line, but those still need a dedicated circuit, and they trade recovery speed for the simpler install. A full panel turns a weekend swap into a licensed electrical job.

Air and water have to go somewhere. A heat pump needs the 1,000 cubic feet and the 40–90°F range above, plus a condensate drain or a pump. A louvered door or a short duct run can rescue a closet; a sealed box cannot.

Gas is not a DIY fuel. A tankless install means gas piping sized to the unit, a vent that meets the manual, and a permit in most jurisdictions. The same goes for the annual descaling that keeps the heat exchanger alive in hard water. This is the line between a project and a call to a plumber.

Plan for the haul-away. Removal and disposal of the old tank is a line item, and so is the drain pan and the expansion tank on a closed system. Ask for those in the quote rather than discovering them on the invoice.

Section 5: What does the project cost, and is the federal credit still there?

The sticker is not the project. Labor, the circuit, the condensate line, the venting and the haul-away are all extra, and the quote depends on the house rather than the product. A $1,699 heat pump with a new 240-volt circuit and a condensate pump is a different project from the same unit swapped onto an existing circuit. The Navien needs venting and gas work on top of $1,949. The Eccotemp needs a vent kit — Eccotemp lists a 3-inch horizontal kit at $319 — and a gas connection. Only the Aquanta is close to its sticker, and even that needs an electrician if you are not comfortable working at the tank.

The federal credit is gone for new installs. The 25C energy efficient home improvement credit covered 30 percent of a heat pump water heater, up to $2,000. ENERGY STAR’s page for the credit now states that it applied to products purchased and installed between January 1, 2023 and December 31, 2025. Any 2026 quote that still subtracts the credit is wrong until an installer shows you a current program. Utility and state rebates are separate and still exist; check the ENERGY STAR Rebate Finder for your ZIP code before you sign.

The energy math still works, slowly. ENERGY STAR estimates that a household of four can save about $600 a year and more than $4,500 over the unit’s life by switching from a standard electric tank to a certified heat pump model, with the price difference paid back in about three years. Rheem’s own figure is up to $576 a year. Treat both as ceilings: they assume high hot water use, typical electric rates and a unit that is not stuck on backup heat in a cold garage.

The cheap options have their own arithmetic. Aquanta at $149 against a $2,000–$3,500 installed heat pump is a different purchase, and the savings are smaller and less certain. The Navien’s $195-a-year gas estimate is Navien’s own, at $1.09 per therm; in a state with expensive gas or a long vent run, the gap to a tank closes.

Maintenance is a cost line too. A heat pump needs its air filter cleaned and its condensate line checked. A tank needs the anode rod inspected and the tank flushed. A tankless unit needs an annual descale. None of it is expensive; all of it is skipped, which is why the maintenance guide exists.

Section 6: What should you buy? (Conclusion)

Buy the Rheem ProTerra 50 at $1,699 if the house is all-electric, the install spot has air and a drain, and the panel has room for a 240-volt circuit. It is the only option here that cuts the energy bill by design rather than by scheduling, it carries a ten-year tank warranty, and the leak shutoff is the feature most likely to save you four figures. Choose the top-connection or 30-amp variant if the layout calls for it and you want the 4.07 UEF rating.

Buy the Navien NPE-240A2 at about $1,949 if the house has gas, three or more bathrooms, and no interest in running out of hot water. Add NaviLink for the app. Budget for venting, gas work and an annual flush, and accept that a power cut means no hot water.

Buy the Eccotemp SHLX at $549 if the demand is one bathroom and the budget is tight. It is the cheapest way here to get a connected gas tankless unit, and it is honest about its limits: 80,000 BTU, 4.5 GPM, a five-year heat exchanger warranty and a smaller service network.

Buy the Aquanta at $149 if the existing tank is under ten years old. It is the best value in this article and the only pick that does not require a plumber, a permit or a new circuit.

Skip all four if the current heater is working, the closet is cold or cramped, and the bill is not a problem. A water heater is a planned purchase; the worst time to make it is the morning the old one leaks. Read the energy audit first to see whether water heating is really where the money goes, and put a leak sensor under the tank in the meantime.

Where to buy

Related reading

• Smart Water Heaters: The Closet Upgrade — heat pump versus resistance versus gas, and the install constraints.
• The Smart Home Energy Audit — find the loads worth replacing.
• Time-of-Use Rates: Automate the Cheap Hours — the schedule a smart tank can use.
• Water Leak Sensors 101 — the cheapest version of the same protection.

Sources

• Rheem: ProTerra Hybrid Electric Heat Pump with LeakGuard — 50-gallon model, 3.88 UEF, ENERGY STAR, 87-gallon first-hour delivery, 10-year tank and parts warranty, built-in Wi-Fi and LeakGuard, 62 inches tall, checked November 2026
• Rheem: Heat Pump Water Heaters — up to 4.07 UEF, up to $576 a year in savings, 40–80 gallon range, 15- and 30-amp models, checked November 2026
• Home Depot: Rheem ProTerra listings — 50-gallon hybrid at $1,699, checked November 2026
• Navien: NPE-240A2 — 199,900 BTU/h, UEF 0.95, 11.2 GPM at 35°F rise, ComfortFlow buffer and recirculation, dimensions, $195 annual gas estimate, checked November 2026
• Navien: NaviLink Wi-Fi Control System — optional Wi-Fi module for remote temperature, usage data and error notifications, checked November 2026
• MyTanklessWaterHeaterStore: Navien NPE-240A2 — $1,949, checked November 2026
• Eccotemp: SmartHome Indoor 4.5 GPM Natural Gas Tankless Water Heater, SHLX Series — $549 sale and $609 list, 4.5 GPM at 80,000 BTU, app with Alexa and Google, five-year heat exchanger warranty, CSA tested, checked November 2026
• Aquanta: Smart Electric and Gas Water Heater Controller — $149, works with nearly all electric and most gas tanks, scheduling, energy tracking, overheat shutoff, optional leak sensor, Alexa and IFTTT, checked November 2026
• ENERGY STAR: Heat Pump Water Heaters Tax Credit — 30 percent up to $2,000, limited to products purchased and installed between January 1, 2023 and December 31, 2025, checked November 2026
• ENERGY STAR: Super-Efficient Water Heater — about $600 a year and $4,500 over the unit’s life for a household of four, three-year payback, checked November 2026
• ENERGY STAR: Heat Pump Water Heaters — 40–90°F room range, 1,000 cubic feet of air space, backup mode in cold weather, checked November 2026