10 Best Tankless Water Heaters With Wi-Fi in 2026 for Smarter Hot Water

Tankless water heaters with Wi-Fi make it easier to monitor temperatures, adjust settings, and troubleshoot hot-water systems from a phone. The best choice depends on fuel type, flow rate, electrical capacity, installation location, and the number of fixtures you use at once.

We compare 10 gas and electric models ranging from compact point-of-use units to high-output whole-home systems, so you can match smart controls with the performance your household actually needs.

Best 10 Tankless Water Heaters with Wifi Picks for 2026

High-Capacity Gas Pick – Rinnai RX199iN Smart Sense

The Rinnai RX199iN is a high-capacity option for shoppers comparing tankless water heaters with wifi, although WiFi control requires the separately sold Controlr module. Its condensing design delivers up to 11.1 GPM and supports natural gas or propane, while Versa Vent allows indoor or outdoor installation with the required outdoor vent cap.

Best For: Large households needing substantial simultaneous hot-water capacity and fuel flexibility.

Pros:

• Up to 11.1 GPM, with capacity for as many as seven fixtures at once.
• Supports either natural gas or propane through the Smart Sense gas control system.
• Compact design, Quick Flush feature, and stated UEF of .98.
• Indoor or outdoor installation flexibility with Versa Vent.

Cons:

• WiFi control is not built in; the Controlr module is sold separately.
• Outdoor installation requires the RX-OVC vent cap.
• Professional installation is recommended.

Choose this model when maximum flow and installation versatility matter more than having WiFi included out of the box. Its warranty terms also depend on registering the product within 90 days of installation.

Flexible App-Controlled Pick – MIZUDO 120,000 BTU

The MIZUDO 120,000 BTU unit is a natural-gas choice for shoppers seeking tankless water heaters with wifi and app management. It provides up to 5.1 GPM, supports two to four usage points, and can be converted between indoor and outdoor installation with separately purchased accessory kits.

Best For: Smaller households that want app control, flexible placement, and stable temperature performance.

Pros:

• Built-in WiFi and app control for temperature adjustments, energy monitoring, and maintenance notifications.
• Temperature stability is designed to remain within ±1°F.
• Indoor or outdoor conversion is possible with the appropriate accessory kit.
• CSA certified with freeze, dry-burn, flame-failure, and exhaust-blockage protection.

Cons:

• Maximum flow is 5.1 GPM, less than higher-capacity models in this roundup.
• Indoor installation requires a 3-inch OD vent system.
• Outdoor conversion accessories are purchased separately.

The MIZUDO stands out when remote monitoring and placement flexibility are priorities. Its 2-year full-unit and 5-year heat-exchanger coverage provide useful protection, but installation accessories add to the project requirements.

Compact Electric Pick – WINTEMP 27kW WiFi

The WINTEMP WN27 is an electric option for shoppers comparing tankless water heaters with wifi. Its self-modulating system delivers up to 6.5 GPM without gas or venting, but the substantial electrical demand means buyers should verify service capacity and consult a qualified electrician before purchase.

Best For: Homes with adequate electrical capacity that want compact, app-enabled hot-water control.

Pros:

• Built-in remote WiFi control and self-modulating temperature management.
• Up to 6.5 GPM for everyday whole-house hot water use.
• Compact wall-mounted design measuring 11.1 by 19.2 by 4 inches.
• ETL certified with leakage, overheat, dry-fire, and child-lock protections.

Cons:

• Requires 240V power, three 40-amp double-pole breakers, and three 8/2 AWG wire runs.
• The notes recommend a 200-amp household service and mention a 250-amp power supply.
• Electrical installation requirements may limit compatibility in some homes.

This model can save wall space and avoids gas-related installation needs, but electrical infrastructure is the key buying consideration. Confirm the required amperage, breakers, and wiring with an electrician before ordering.

Built-In Smart Gas Pick – Westinghouse 7.9 GPM

The Westinghouse 7.9 GPM natural-gas unit is a practical contender among tankless water heaters with wifi, offering built-in app and voice control without an extra module. It is designed for indoor whole-house use, supplies up to three showers at once, and maintains temperature within ±1°F.

Best For: Households wanting built-in smart controls, dependable low-flow activation, and moderate whole-home capacity.

Pros:

• Built-in WiFi app and voice control with remote temperature adjustment and fault alerts.
• 7.9 GPM output and 180,000 BTU capacity for up to three showers simultaneously.
• ±1°F temperature stability through self-modulating gas and water flow.
• Activates at flow rates as low as 0.53 GPM and operates down to 15 PSI.

Cons:

• Specified for indoor natural-gas installation rather than propane or outdoor use.
• Requires standard 3/4-inch NPT plumbing and 120V AC power.
• Professional installation considerations remain important for a gas appliance.

The Westinghouse is a well-rounded choice when built-in connectivity matters. Its low-flow activation may also suit homes with private wells, older plumbing, or low-flow fixtures, provided the indoor natural-gas installation requirements fit.

High-Capacity Electric Pick – 36kW Whole-House WiFi Tankless Heater

For shoppers comparing tankless water heaters with wifi, the WINTEMP WN36 stands out as a high-output electric option with smartphone temperature control. Its self-modulating design supports up to 8.7 GPM, but the substantial electrical requirements make professional planning essential.

Best For: Homes with 3–5 bathrooms in mild to moderate climates that have adequate electrical service for a 36kW whole-house unit.

Pros:

• Provides up to 8.7 GPM of on-demand hot water.
• Built-in WiFi enables smartphone temperature control.
• Self-modulating technology adjusts output to flow and incoming-water temperature.
• Compact wall-mounted design with leakage, overheat, and dry-fire protection.

Cons:

• Requires a recommended 300A household electrical service.
• Needs four 40A double-pole breakers and four 8/2 AWG cables with ground.
• Its high electrical demand may not suit homes with limited service capacity.

The WN36 offers strong whole-house capacity and convenient WiFi control, but its installation requirements are unusually demanding. Verify your electrical system and consult a licensed electrician before purchasing.

Outdoor Propane Pick – APUS 190,000 BTU WiFi Tankless Heater

Among tankless water heaters with wifi, this APUS propane model is designed for outdoor whole-house use. It delivers up to 8.1 GPM, supports multiple outlets, and offers app or wired-controller temperature adjustments from 95°F to 149°F.

Best For: Households seeking an outdoor propane heater for supplying several hot-water outlets simultaneously, including homes with weaker water pressure.

Pros:

• 190,000 BTU output and up to 8.1 GPM flow for 5–6 outlets.
• WiFi control through the Tuya app plus an optional wired controller.
• Low 0.79 GPM minimum flow supports operation with weak water pressure.
• Includes freeze, overheat, and flame-failure safeguards.

Cons:

• Requires liquid propane and outdoor installation.
• WiFi control depends on the Tuya app.
• Professional installation may be needed for gas, water, and electrical connections.

This APUS heater combines high flow capacity with remote control and freeze protection. Its propane fuel and outdoor configuration should be matched to your home’s existing setup and local installation requirements.

Smart Point-of-Use Pick – Westinghouse 11kW WiFi Tankless Heater

For shoppers seeking compact tankless water heaters with wifi, this Westinghouse 11kW electric model is built for a single point of use. It heats water in about three seconds, reaches up to 2.6 GPM under the stated conditions, and works with Alexa and Google Home.

Best For: A single shower, sink, or other point of use in an apartment, cabin, office restroom, or similar space.

Pros:

• Smart WiFi, app control, and Alexa/Google Home compatibility.
• Temperature memory restores the previous setting after a power outage.
• Compact wall-mounted design with 98% stated thermal efficiency.
• ETL certification and protection against leakage, overheating, dry fire, and over-voltage.

Cons:

• Limited to one point of use and a maximum stated flow of 2.6 GPM.
• Requires a dedicated 60A double-pole breaker and 8 AWG wire at 240V.
• Performance depends on inlet temperature and the selected outlet temperature.

This Westinghouse unit is a practical smart-home choice when you need compact electric heating for one outlet. Its dedicated-circuit requirement should be confirmed before installation.

Flexible Propane Pick – MIZUDO 5.1 GPM WiFi Propane Heater

For shoppers comparing tankless water heaters with wifi, the MIZUDO stands out for combining app control with propane-powered whole-house capacity. Its 120,000 BTU output and 5.1 GPM flow rate are designed for simultaneous use at multiple fixtures, while its convertible indoor/outdoor installation adds flexibility.

Best For: Larger households needing propane-powered hot water for two to four usage points.

Pros:

• WiFi and app control for temperature adjustments, energy monitoring, and maintenance notifications.
• 5.1 GPM capacity and 120,000 BTU output support multiple bathrooms and fixtures.
• Indoor or outdoor convertible installation with the appropriate accessory kit.
• Includes freeze, dry-burn, flame-failure, and exhaust-blockage protection.

Cons:

• Indoor installation requires a 3-inch outside-diameter vent pipe system.
• Outdoor conversion requires a separately purchased vent-cap kit.
• Propane installation may require more planning than an electric model.

The MIZUDO is a strong option when you want smart controls and higher flow for a propane whole-house system. Confirm venting, fuel, and installation requirements before ordering.

Compact Electric Value – WINTEMP 18kW WiFi Tankless Heater

Among tankless water heaters with wifi, the WINTEMP WN18 offers compact electric operation with remote temperature control. Its self-modulating design adjusts power based on water flow and incoming temperature, providing up to 4.3 GPM for residential hot-water use.

Best For: Two- to three-bathroom homes in mild to moderate climates with adequate electrical service.

Pros:

• WiFi control lets you adjust the temperature remotely.
• Self-modulation helps match power use to flow and incoming water temperature.
• Compact wall-mounted design takes substantially less space than a traditional tank.
• ETL certification and leakage, overheat, and dry-fire protection add safety features.

Cons:

• Requires 240V service, two 40-amp double-pole breakers, and specified heavy-gauge wiring.
• The manufacturer recommends a 150-amp household service.
• Maximum flow is dependent on incoming water temperature and household demand.

The WN18 makes sense for buyers who want an electric, space-saving unit with app access. Have a qualified electrician verify panel capacity and installation requirements before purchase.

Smart-Home Electric Pick – Westinghouse 18kW WiFi Heater

The Westinghouse ET018CA0G is a practical choice among tankless water heaters with wifi, especially for shoppers who use Alexa or Google Home. It offers 18kW electric heating, a digital LED display, app-based adjustments, and a compact form factor, though available flow depends on the incoming water temperature.

Best For: Compact installations where smart-home compatibility and precise temperature adjustment are priorities.

Pros:

• WiFi control works with Alexa and Google Home for remote adjustments.
• Temperature can be set from 86°F to 140°F in 1°F increments.
• Copper heating elements and a supplied scale inhibitor support fast heating and buildup reduction.
• ETL certified with overheat, dry-fire, and leak protection.

Cons:

• Requires 240V hard wiring and a 75-amp electrical setup.
• Flow ranges from 2.6 to 4.2 GPM depending on inlet temperature.
• Professional installation is recommended, and panel capacity should be verified.

This Westinghouse model is appealing when voice-assistant integration and a slim design matter more than maximum flow. Review the electrical requirements and expected inlet temperature to ensure it fits your installation.

How We Picked the Best Tankless Water Heaters with Wifi

We evaluated the selected models by heating capacity, maximum flow rate, fuel type, installation flexibility, smart-control features, temperature range, and intended use. We also considered whether each unit is designed for whole-home demand or a single fixture. Product specifications such as BTU or kilowatt rating, voltage requirements, maximum gallons per minute, and indoor or outdoor installation support are especially important because Wi-Fi cannot compensate for an undersized heater or an incompatible utility setup.

Availability of professional installation, local code requirements, gas-line capacity, venting, water quality, and electrical service should be confirmed before purchase. Manufacturer claims for maximum flow generally assume favorable incoming-water temperatures and may be lower in colder climates.

Quick Comparison

Best suited for	Recommended type	What to prioritize
Large households	High-output gas	At least 7 GPM, adequate BTU capacity, reliable recirculation or temperature control
Homes without gas service	27kW–36kW electric	Available amperage, multiple 240V circuits, realistic cold-water flow
Small homes or apartments	18kW electric or compact gas	Moderate flow demand, simple controls, installation compatibility
One sink or shower	11kW point-of-use electric	Low operating cost, compact size, correct circuit capacity
Outdoor installations	Propane or outdoor-rated gas	Freeze protection, weather rating, propane supply, remote controls

Key Buying Factors for Tankless Water Heaters with Wi-Fi

Fuel and Installation Requirements

Gas models usually deliver higher flow rates but require proper venting, combustion air, gas supply, and professional installation. Electric units avoid combustion and venting, but larger models can require several dedicated 240-volt circuits and may exceed the capacity of an older electrical panel.

Flow Rate and Temperature Rise

Estimate simultaneous demand rather than relying only on the advertised maximum GPM. Add the flow rates of showers, faucets, and appliances that may run together, then account for the temperature rise needed in your climate. A unit that works well in a warm region may provide less usable flow when incoming water is very cold.

Wi-Fi Functions

Smart features commonly include remote temperature adjustment, scheduling, usage monitoring, alerts, diagnostics, and maintenance reminders. Check whether the unit requires a dedicated app, a stable 2.4GHz network, or an optional accessory. Confirm that local controls remain available if the internet connection fails.

Maintenance and Protection

Tankless systems typically need periodic descaling, particularly with hard water. Look for accessible service components, scale protection, freeze protection where appropriate, and clear error reporting. Gas units also need attention to venting and combustion components.

Who Should Buy Which Tankless Water Heaters with Wifi?

Choose a high-output gas model if your household runs several showers or fixtures simultaneously and you already have compatible gas service. Select a 27kW or 36kW electric model only after an electrician verifies the panel and circuit requirements. An 18kW electric unit is better suited to moderate demand, while an 11kW model makes more sense for a single bathroom, sink, or other point-of-use application. For outdoor use, propane models can be practical where venting or natural-gas access is limited, provided freeze protection and fuel storage are addressed.