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

The best tankless water heaters with leak detection deliver hot water on demand while helping you spot or limit water damage before a small issue becomes an expensive repair.

This roundup compares gas, propane, electric, portable, and point-of-use options by capacity, installation requirements, efficiency, controls, and safety features.

Best 10 Tankless Water Heaters with Leak Detection Picks for 2026

Best Whole-Home Gas Pick – Rheem RTG 9.5 GPM WiFi

For shoppers comparing tankless water heaters with leak detection, the Rheem RTG Series stands out as a high-capacity indoor natural gas option. Its 9.5 GPM output, WiFi connectivity, and LeakGuard Leak Detection and Prevention System suit larger households that need substantial hot-water capacity and added monitoring.

Best For: Large families and multi-bathroom homes with several hot-water outlets running at once.

Pros:

• 9.5 GPM flow rate and 199,900 BTU output support 3–4 simultaneous showers.
• LeakGuard leak detection and prevention system, WiFi, and hot-start programming.
• Includes freeze and flame-failure protection, plus a 15-year heat exchanger warranty and 5-year parts warranty.

Cons:

• Requires professional installation and an indoor direct-vent setup.
• Uses natural gas rather than electricity or propane.
• Its high capacity may be more than smaller households need.

This is a strong choice when whole-home capacity and leak-related protection are priorities. Confirm that your home has the required natural-gas supply, venting, and professional installation support before buying.

Best Compact Propane Option – Rinnai V53DeP 5.3 GPM

The Rinnai V53DeP is a compact outdoor propane unit for buyers who want tankless water heaters with leak detection-related monitoring features in a space-saving design. Its enhanced scale detection, 5.3 GPM flow rate, and outdoor installation format make it practical for moderate residential hot-water needs.

Best For: Households needing a compact outdoor propane heater for multiple appliances or typical residential use.

Pros:

• 5.3 GPM flow rate provides continuous hot water for multiple appliances.
• Compact outdoor design helps conserve installation space.
• Enhanced scale detection and optional WiFi capability support ongoing monitoring and maintenance.

Cons:

• The supplied details do not identify a dedicated leak-detection system.
• Professional installation is recommended.
• Propane fuel is required, and output is lower than the 9.5 GPM Rheem option.

The V53DeP is best viewed as a compact propane solution with scale-focused monitoring rather than a clearly specified leak-prevention model. Check the installation requirements and warranty-registration terms, since labor coverage depends on registration.

Best Electric Value – Rheem RTEX-18 18kW

The Rheem RTEX-18 is a straightforward electric tankless water heater for buyers who prioritize efficient on-demand heating and simple controls. It is not specifically listed with leak detection, so shoppers seeking tankless water heaters with leak detection should treat this as an electric performance option rather than a leak-monitoring specialist.

Best For: Buyers wanting a compact electric unit with self-modulation and precise digital temperature control.

Pros:

• 99.8% listed efficiency and self-modulation adjust power to hot-water demand.
• External digital thermostat provides temperature adjustment with ±1-degree accuracy.
• Field-serviceable copper immersion heating elements and simple bottom water connections.

Cons:

• The supplied specifications do not list leak detection or leak prevention.
• Maximum listed flow rate is 4.4 GPM, below the larger gas models in this roundup.
• Requires a 240-volt electrical connection.

This model makes sense for homes suited to electric installation and moderate hot-water demand. If leak alerts are essential, plan to verify whether an external monitoring solution or a different Rheem model is needed.

Best Portable Leak-Detection Pick – 8L Portable Propane Heater

This portable 8L propane heater is a practical choice for shoppers seeking tankless water heaters with leak detection for temporary outdoor, RV, camping, or utility use. It lists leak detection among its safety features and adds protection against overheating, dry combustion, freezing, low flow, flame faults, and high water pressure.

Best For: Camping, RV use, pet washing, car washing, and other temporary outdoor hot-water tasks.

Pros:

• Includes leak detection plus six listed safety protections.
• Portable, lightweight design delivers up to 2.11 GPM at 40,824 BTU/hour.
• Digital display and one-button shower head support convenient temporary use.

Cons:

• Its 2.11 GPM output is unsuitable for most whole-home applications.
• Maximum listed temperature is 113°F.
• Although indoor use is mentioned, the supplied notes emphasize outdoor, camping, RV, and temporary applications; installation suitability should be confirmed.

Choose this unit for portability and listed leak detection rather than household-scale capacity. Its safety package and compact format are useful away from home, but the modest flow rate limits it to targeted tasks.

Compact Electric Pick – Rheem 8kW Multi-Fixture Tankless Water Heater

For shoppers comparing tankless water heaters with leak detection, this Rheem electric model is a compact point-of-use option with a five-year leak warranty. The 8kW unit delivers up to 1.95 GPM and uses digital thermostatic controls, but its 240V electrical requirements should be verified before installation.

Best For: Point-of-use applications serving multiple fixtures where a 240V electrical circuit is available.

Pros:

• Provides up to 1.95 GPM for multiple-fixture applications.
• Digital temperature adjustment in one-degree increments from 80°F to 140°F.
• Compact wall-mounted design is about 90% smaller than a traditional tank heater.
• Includes a five-year leak and one-year parts warranty.

Cons:

• Requires 240V single-phase power, a 40-amp double-pole breaker, and #8 AWG copper conductors.
• Rheem recommends at least a 100-amp household electrical service panel.
• Its 1.95 GPM output is better suited to point-of-use needs than whole-home demand.

This is a practical space-saving choice when the home’s electrical system can support it. Its leak warranty is useful for buyers prioritizing protection, although the specifications do not list an electronic leak-detection feature.

Whole-Home LP Pick – Rheem RTG 8.4 GPM Indoor Propane Heater

Among tankless water heaters with leak detection, this Rheem RTG model stands out for whole-home capacity and a listed leak-detection feature. It runs on liquid propane, produces up to 8.4 GPM at a 35°F temperature rise, and is designed for indoor installation with professional installation required.

Best For: Large households needing simultaneous hot water for multiple showers and fixtures.

Pros:

• 8.4 GPM flow and 180,000 BTU output support up to three or four simultaneous showers according to the supplied specifications.
• Includes leak detection along with freeze, flame-failure, and multi-point safety protection.
• Non-condensing design has a listed 0.82 UEF and is rated to save up to 34% versus a 50-gallon electric tank heater.
• Offers a 15-year heat-exchanger warranty and five-year parts warranty.

Cons:

• Uses liquid propane and requires indoor direct-vent installation.
• Professional installation is required.
• The unit is substantially larger and heavier than point-of-use electric models.

With its high flow rate and built-in leak detection, this is the strongest match here for buyers seeking whole-home performance and added monitoring. Confirm venting, propane availability, and installation requirements before purchasing.

Small-Sink Value Pick – CAMPLUX 4.5kW 120V Point-of-Use Heater

For a small sink installation, this CAMPLUX electric unit offers fast point-of-use heating in a very compact package. It is worth comparing carefully with other tankless water heaters with leak detection because the supplied features list dry-combustion protection but does not identify an electronic leak-detection function.

Best For: A single sink in a kitchen, wet bar, boat, salon, or other space with limited room.

Pros:

• Compact wall-mounted dimensions fit tight installation spaces.
• Self-modulating operation adjusts power based on flow rate and temperature settings.
• LED touch controls make temperature selection straightforward.
• Activates at a minimum flow of 0.26 GPM and has a two-year limited warranty.

Cons:

• Designed for only one sink and provides a listed 50°F temperature rise at 1.0 GPM.
• Must be hardwired; it requires a 40-amp circuit breaker and 10 AWG wire.
• The 120V, 4.5kW design is not intended for whole-home hot-water demand.

This lightweight heater makes sense where space is tight and hot water is needed at one sink. Its dry-combustion protection adds a safety feature, but buyers specifically requiring leak detection should verify that capability before choosing it.

Best Compact High-Efficiency Pick – ORBEK 14kW Electric Tankless Water Heater

If you need tankless water heaters with leak detection for a compact installation, the ORBEK 14kW model combines leakage protection with on-demand heating and a slim wall-mounted design. It delivers up to 3.38 GPM and requires a 240V circuit with a 60A two-pole breaker, 6 AWG wiring, and 1/2-inch NPT connections.

Best For: Small households needing hot water for two or three points of use, such as a bathroom and kitchen.

Pros:

• Leakage, over-temperature, and dry-heating protection, plus ETL certification.
• Provides up to 3.38 GPM with claimed three-second heating and 98% efficiency.
• Compact 3.1-inch-deep design and LED temperature display with 1°F adjustment.

Cons:

• Requires a substantial 240V/60A electrical circuit and 6 AWG wiring.
• The maximum flow rate may be limiting for higher-demand simultaneous use.

The ORBEK is a practical choice when limited space and built-in leak protection matter. Confirm that your electrical panel has at least 150 amps of total capacity and arrange professional installation for the required hard-wired circuit.

Best for Higher Flow – NOVIEEX 18kW Electric Tankless Water Heater

The NOVIEEX 18kW is one of the stronger options among tankless water heaters with leak detection when multiple fixtures may run at once. Its maximum stated flow is 4.9 GPM, while the eight-layer safety system includes leakage protection, over-temperature cutoff, grounding protection, and fault self-diagnosis.

Best For: Small-to-medium homes, apartments, and condos needing hot water for two or three simultaneous uses.

Pros:

• High 4.9 GPM maximum flow for showers, kitchen use, and laundry demand.
• Includes leakage protection, dry-combustion prevention, over-pressure relief, and IPX4 waterproofing.
• Adjustable 77°F to 140°F temperature range with 1°F increments and LED display.

Cons:

• Requires two 40A double-pole breakers, two sets of 8 AWG wiring, and a ground wire.
• Its 75A maximum current makes electrical-system compatibility especially important.

With its higher flow rating and broad safety package, the NOVIEEX is suited to busier small homes. Have a qualified electrician verify the service capacity and install the required circuits before purchase.

Best Point-of-Use Option – 6500W Under-Sink Electric Water Heater

For a kitchen, bathroom, laundry area, or RV, this 6500W point-of-use unit is a focused option among tankless water heaters with leak detection. It includes leak detection, dry-burn protection, automatic self-diagnosis, and a compact wall-mount design, while its touch controls and remote make temperature adjustments straightforward.

Best For: Point-of-use installations under sinks and other locations with modest hot-water requirements.

Pros:

• Built-in leak detection, dry-burn protection, self-diagnosis, and IPX4 waterproofing.
• Compact 2.34-inch-wide design with digital touch controls and included remote.
• Adjustable 80°F to 131°F temperature range with memory function and dual-unit display.

Cons:

• Its 6,500W output and point-of-use format are less suited to whole-home demand.
• Requires a dedicated 240V circuit, 30A double-pole breaker, and 10 AWG copper wire.
• The maximum stated temperature is 131°F.

This model makes the most sense when you want localized hot water without a storage tank. Its lower power demand than the larger units does not eliminate installation requirements, so use a licensed electrician and verify the dedicated circuit before installation.

How We Picked the Best Tankless Water Heaters with Leak Detection

We evaluated the 10 selected models for practical fit rather than headline specifications alone. Our comparison considers fuel type, maximum flow rate, heating capacity, installation flexibility, controls, energy efficiency, and the kind of household each unit can realistically serve. We also looked for safety-minded features such as leak alerts, automatic shutoff compatibility, diagnostic displays, temperature protection, and installation designs that make maintenance easier.

Because product listings do not always describe leak detection in the same way, verify the exact feature in the current manufacturer documentation. Some heaters include built-in sensors, while others rely on an optional leak detector, isolation valve, or smart-home accessory.

Quick Comparison

• Best for larger homes: High-output natural-gas or propane models can support multiple fixtures when properly sized and installed.
• Best for smaller spaces: Electric units avoid combustion venting and can fit closets, additions, apartments, or utility areas where adequate electrical service is available.
• Best for a single sink: Point-of-use and under-sink heaters reduce wait times without replacing a whole-home system.
• Best for temporary or remote use: Portable propane models are useful for cabins, campsites, workshops, and off-grid applications, subject to ventilation and local safety rules.

Key Buying Factors for Tankless Water Heaters with Leak Detection

Fuel Type and Installation

Gas and propane heaters generally provide higher flow rates, but they require suitable venting, fuel lines, combustion air, and professional installation. Electric models are often simpler to vent because they produce no combustion exhaust, but many require a dedicated 240-volt circuit, substantial amperage, and an electrical panel capable of handling the load.

Flow Rate and Temperature Rise

Do not choose by GPM alone. A unit’s real output depends on incoming water temperature and the desired temperature rise. Estimate simultaneous demand from showers, faucets, and appliances, then choose a model that can meet that demand in your climate. Smaller units are usually better for one fixture or limited use.

Leak Protection and Controls

Look for clear information about leak sensors, automatic shutoff, alarm notifications, fault codes, and remote monitoring. A leak detector is valuable, but it cannot replace proper installation, pressure regulation, a drain pan where appropriate, and routine inspection of connections and valves.

Efficiency, Maintenance, and Warranty

Compare efficiency ratings, standby-energy savings, scale protection, filter access, descaling requirements, and warranty coverage. Hard water can reduce performance, so plan for filtration or periodic flushing if recommended by the manufacturer.

Who Should Buy Which Tankless Water Heaters with Leak Detection?

Choose a high-output gas or propane model for a family home with several simultaneous hot-water demands and the right venting infrastructure. Choose a 14kW–18kW electric model for a smaller household or renovation when the electrical service supports its requirements. Select an 8kW class unit for limited multi-fixture use, and choose an under-sink or point-of-use heater for one faucet, office, garage, or accessory space. Portable propane models make the most sense where mobility matters, but they require especially careful attention to ventilation, connections, and local regulations.