10 Best Tankless Water Heaters With Leak Detection for Safer, Efficient Hot Water in 2026

Tankless water heaters with leak detection add an important layer of protection to endless hot water. They help catch problems early, which can reduce water damage and costly repairs.

In this roundup, we focus on models that balance performance, efficiency, smart features, and installation flexibility for different homes and fuel types.

Best 10 Tankless Water Heaters with Leak Detection Picks for 2026

Smart Efficiency Pick – Rinnai RX130iN Condensing Smart Sense Tankless Water Heater

The Rinnai RX130iN is a strong fit for shoppers comparing tankless water heaters with leak detection and wanting a condensing, smart-connected model. Its Smart Sense positioning points to a more modern control experience, while the tankless format is designed for continuous hot water in a compact footprint.

Best For: Buyers who want a premium condensing tankless unit with smart features.

Pros:

• Condensing design for higher-efficiency operation.
• Smart Sense branding suggests app- or sensor-driven convenience.
• Tankless format helps save space versus a storage tank.
• Suitable for buyers prioritizing a modern feature set.

Cons:

• Product notes provided do not specify leak-detection details.
• Condensing units can be more involved to plan for than basic models.
• Premium feature sets may not suit budget-focused shoppers.

This model makes sense if you want a higher-end tankless water heater with a smart-focused identity and condensing efficiency. For leak detection specifically, you’ll want to confirm the exact protection features in the listing before buying.

High-Flow Connectivity Pick – Noritz GQ-C3261WX-FF 11.1 GPM Tankless Water Heater

The Noritz GQ-C3261WX-FF is a strong option in tankless water heaters with leak detection searches if you also want a high-output gas model with Bluetooth connectivity. With an 11.1 GPM rating and indoor/outdoor residential positioning, it is aimed at households that need more capacity and flexible installation options.

Best For: Homes that need high hot-water output and connected control features.

Pros:

• 11.1 GPM capacity supports demanding hot-water use.
• Bluetooth connectivity adds convenient control potential.
• Indoor/outdoor residential design offers installation flexibility.
• 120-volt operation may simplify power requirements.

Cons:

• Product notes provided do not mention leak-detection capability.
• Gas tankless models may require more installation planning.
• High-output systems may be more than some small households need.

If output and connectivity matter most, this Noritz model deserves consideration. Buyers focused on leak detection should verify whether that feature is included separately, since it is not stated in the supplied notes.

Budget Electric Pick – 18kW Electric Tankless Water Heater 240V ETL Certified WiFi

This 18kW electric tankless water heater is a practical choice for buyers comparing tankless water heaters with leak detection and wanting WiFi-enabled convenience. Its ETL certification and 240V electric setup make it a straightforward feature set for shoppers looking at a compact on-demand unit.

Best For: Shoppers who want an electric tankless unit with WiFi control.

Pros:

• 18kW output in a tankless electric format.
• WiFi capability adds remote convenience.
• ETL certification supports buyer confidence.
• 240V design fits common electric installation setups.

Cons:

• Product notes provided do not mention leak detection.
• Electric tankless units depend on adequate electrical capacity.
• 18kW may not match the output needs of larger households.

For buyers who want WiFi and a simpler electric path, this model is easy to shortlist. If leak detection is a priority, confirm that feature separately, because it is not specified in the provided product details.

Propane Performance Pick – Rheem RTG Series 8.4 GPM LP Tankless Water Heater

The Rheem RTG Series is a practical propane tankless choice for shoppers evaluating tankless water heaters with leak detection and wanting strong flow from a non-condensing design. With 8.4 GPM and 180,000 BTUs, it is positioned as a continuous hot-water solution for indoor use.

Best For: Homes using liquid propane that want high-efficiency on-demand hot water.

Pros:

• 8.4 GPM supports steady hot-water delivery.
• 180,000 BTUs provide strong heating output.
• Indoor LP configuration suits propane-equipped homes.
• High-efficiency on-demand design delivers continuous hot water.

Cons:

• Product notes provided do not mention leak detection.
• Non-condensing design may not appeal to efficiency-first shoppers.
• Indoor installation limits placement compared with outdoor-friendly models.

This Rheem model is a solid fit when propane supply and hot-water performance are the main priorities. As with the others in this roundup, confirm leak-detection features directly if that is a must-have.

Electric Compact Pick – Westinghouse 11kW Tankless Water Heater

If you want a tankless water heater with leak detection in a compact electric format, the Westinghouse 11kW model is a straightforward fit for smaller hot-water needs. It adds WiFi and ETL certification, making it a practical choice for buyers who want app-connected convenience in an indoor electric unit.

Best For: Small homes, point-of-use installs, or buyers who want a WiFi-enabled electric tankless unit with compact sizing.

Pros:

• 11kW electric design for straightforward indoor use
• WiFi enabled for added convenience
• ETL listed for an added safety/certification checkpoint
• Compact option for smaller hot-water demands

Cons:

• Electric output is better suited to lighter-demand applications
• Leak detection is not stated in the supplied product details
• Not intended for large household peak-demand use

Overall, this Westinghouse unit is best viewed as a simple, tech-friendly electric tankless option. If your priority is a compact setup and WiFi connectivity, it offers a clean shortlist candidate, but shoppers specifically seeking leak-detection features should verify that separately.

High-Flow Gas Pick – Rheem RTG 9.5 GPM Tankless Water Heater

For shoppers comparing tankless water heaters with leak detection, this Rheem RTG Series model stands out for its high-flow natural gas setup and indoor installation design. With 9.5 GPM, 199,900 BTUs, and WiFi enabled controls, it is aimed at continuous hot-water delivery in larger-demand homes.

Best For: Larger households that need strong continuous hot-water output from an indoor natural gas tankless unit.

Pros:

• 9.5 GPM flow rate for higher-demand use
• 199,900 BTUs supports strong heating capacity
• WiFi enabled for connected control
• High-efficiency on-demand hot water delivery

Cons:

• Indoor natural gas installation only
• Non-condensing design may not suit every efficiency preference
• Leak detection is not listed in the supplied product details

This Rheem model is a solid fit if your priority is performance and continuous hot water rather than a feature-heavy safety package. It is well-positioned for homes that need strong throughput, but buyers should confirm leak-detection needs separately because that capability is not specified here.

Propane Indoor Value – Westinghouse 120,000 BTU Propane Tankless Heater

If you are shopping for tankless water heaters with leak detection, this Westinghouse propane model is a compact indoor option with a 120,000 BTU rating and 5.1 GPM flow. It is designed for propane setups where moderate hot-water delivery is enough for everyday use.

Best For: Indoor propane installations that need moderate flow in a smaller or mid-size home.

Pros:

• 120,000 BTU propane tankless design
• 5.1 GPM is suitable for moderate demand
• Indoor installation format
• Westinghouse branding for a recognizable option

Cons:

• Lower flow than larger high-demand tankless units
• Propane-specific installation limits placement options
• Leak detection is not stated in the supplied product details

This unit makes sense when propane compatibility matters more than maximum output. It offers a balanced flow rating for everyday use, but shoppers specifically seeking leak-detection capability will need to verify that feature elsewhere because it is not included in the provided details.

Outdoor High-Flow Gas Pick – Rheem RTG Series 9.5 GPM

If you’re comparing tankless water heaters with leak detection, this Rheem RTG outdoor model is built around high-output, continuous hot water for whole-home use. It delivers up to 9.5 GPM with 199,900 BTUs, while WiFi connectivity adds convenient control for everyday operation.

Best For: Homeowners who want an outdoor natural gas tankless heater with strong flow and app-connected convenience.

Pros:

• 9.5 GPM output supports continuous hot water for multiple uses
• 199,900 BTUs provides high heating capacity
• Outdoor installation saves indoor space
• WiFi enabled for connected control

Cons:

• Natural gas only, so it is not a propane option
• Outdoor design may not fit every installation plan

This model fits buyers prioritizing high flow and efficient on-demand performance in an outdoor format. If leak detection is a must-have, be sure to verify the exact safety features separately, since the supplied specs focus on capacity, efficiency, and WiFi control.

Indoor Whole-Home Value Pick – MIZUDO 10.3 GPM Natural Gas

For shoppers comparing tankless water heaters with leak detection, this MIZUDO natural gas unit stands out for its high-flow, whole-home design and app-based controls. It is rated at 199,000 BTU and up to 10.3 GPM, making it suited to homes that need strong demand coverage from one indoor system.

Best For: Households looking for a high-capacity indoor natural gas tankless heater with WiFi and app control.

Pros:

• 10.3 GPM supports multiple outlets and whole-home use
• 199,000 BTU output for high-flow performance
• WiFi and app control add convenience
• Anti-freeze feature helps support cold-weather operation

Cons:

• Indoor installation requires the right setup and venting plan
• Temperature range is limited to 95-149°F

This is a practical pick if your priority is strong hot-water delivery for several fixtures at once. As with the other models here, the supplied product details do not specifically confirm leak detection, so that should be checked separately if it is a required feature.

High-Efficiency Propane Option – Rheem RTGH Series 9.5 GPM

If you want tankless water heaters with leak detection in a propane setup, this Rheem RTGH indoor model is aimed at efficient on-demand hot water with a very strong output rating. It delivers up to 9.5 GPM and 199,900 BTUs, and its condensing, ultra-low NOx design is built for high-efficiency continuous use.

Best For: Buyers who need an indoor liquid propane tankless heater with high efficiency and WiFi connectivity.

Pros:

• 9.5 GPM supports continuous hot water demand
• 199,900 BTUs for high-output performance
• Condensing, ultra-low NOx design
• WiFi enabled for connected control

Cons:

• Indoor installation means more planning than an outdoor unit
• Liquid propane only, so it is not a natural gas model

This model is a strong fit if you want propane fuel and a high-efficiency indoor unit for continuous hot water. The available specs emphasize performance and connectivity, but they do not explicitly list leak detection, so confirm that feature if it is essential to your purchase.

How We Picked These Tankless Water Heaters with Leak Detection

We prioritized models that combine practical leak-awareness features with strong heating performance, reputable brands, and homeowner-friendly controls. We also considered fuel type, venting needs, flow rate, and whether the unit is better suited for a single bath, a busy family home, or larger whole-house demand.

Because leak detection is only one part of the buying decision, we looked at how well each unit supports safe, efficient everyday use. That includes WiFi/app support, durable construction, energy-saving operation, and installation formats that fit indoor or outdoor setups.

Quick Comparison

For higher hot-water demand, gas models generally offer the strongest flow rates and recovery. Electric units can be simpler in some installations and are often better for smaller homes or point-of-use needs, but they may require substantial electrical capacity.

If you want one system to serve multiple showers and appliances at once, compare GPM ratings, BTU output, and whether the model is indoor or outdoor rated. If efficiency and smart controls matter most, look for models with app connectivity and clear maintenance alerts.

Key Buying Factors for Tankless Water Heaters with Leak Detection

Flow Rate and Household Demand

Choose a unit sized for peak use, not average use. A larger household or home with multiple bathrooms usually needs a higher GPM rating to avoid temperature drops during simultaneous use.

Fuel Type and Electrical Requirements

Natural gas and propane models typically deliver higher output, while electric units may be easier to place but can demand large amperage and dedicated circuits. Match the heater to what your home already supports.

Leak Detection and Smart Monitoring

Leak detection features are most valuable when they provide timely alerts, easy status checks, or automatic shutdown support. WiFi-enabled models can make monitoring easier, especially if the heater is in a garage, attic, or utility closet.

Installation Location and Venting

Indoor and outdoor models are not interchangeable. Confirm venting, freeze protection, clearances, and local code requirements before buying. The right location can affect both safety and long-term reliability.

Who Should Buy Which Tankless Water Heaters with Leak Detection?

If you want maximum whole-home performance, choose a high-output gas model. If you need a simpler setup for a smaller household, an electric unit may be the better fit. Homeowners who value remote monitoring and convenience should favor Tankless Water Heaters with Leak Detection that include WiFi or app controls.

In short, the best pick depends on your fuel source, hot-water demand, and where the unit will be installed. Start with sizing, then use leak detection and smart features to narrow the field.