Tankless water heaters can save space, cut standby energy use, and deliver hot water on demand, but leak protection matters just as much as performance.
In this roundup, we focus on tankless water heaters with leak detection and other safety-minded features to help you choose a model that fits your home, budget, and installation needs.
Best 10 Tankless Water Heaters with Leak Detection Picks for 2026
Whole-Home Smart Pick
Westinghouse 7.9 GPM Gas Indoor
- 7.9 GPM and 180,000 BTU output
- WiFi app control with fault alerts
- ±1°F temperature stability and low-flow start
Best For: Larger homes needing smart indoor gas hot water
Compact Safety Choice
- Leakage, dry-heating, and over-temp protection
- Up to 3.38 GPM for 2-3 points of use
- Compact wall-mounted design
Best For: Homes wanting a compact electric unit with leak protection
Portable Outdoor Option
- Leak detection with six safety protections
- 2.11 GPM and 40,824 BTU output
- Portable design for RV and camping use
Best For: Campers and RV users needing portable leak-aware hot water
High-Output Electric Pick
- Up to 4.4 GPM flow rate
- LED thermostatic control with ±1° accuracy
- 99.8% efficiency and self-modulation
Best For: Buyers wanting a precise, high-output electric heater
Best for Easy Setup
- Leak detection with six safety protections
- Compact propane design for outdoor use
- Up to 3.66 GPM and 85,300 BTU output
Best For: Outdoor buyers who need a portable propane tankless heater with leak detection
Smart Electric Pick
Westinghouse 14kW WiFi Tankless
- Leakage protection in a 4-layer safety system
- WiFi, app, Alexa, and Google Home control
- Compact wall-mount unit with fast heating
Best For: Small homes and apartments that want smart controls and leakage protection
Whole-Home Gas Pick
- LeakGuard detects and helps prevent internal leaks
- 7.0 GPM supports multiple showers at once
- 160,000 BTU output for whole-house use
Best For: Large households that need strong indoor gas performance with leak protection
High-Capacity Safety Pick
Rheem RTG 8.4 GPM LP Indoor Heater
- 8.4 GPM LP tankless unit for whole-home use
- Built-in leak detection plus freeze protection
- Digital LED controls with ±1°F adjustment
Best For: Large homes needing continuous hot water and safety features
Smallest Leak-Protection Pick
Mini 3kW Plug-In Under-Sink Heater
- 3kW 120V plug-in heater for low-flow sinks
- Leakage protection plus overheat and dry-heating protection
- Compact body with knob and LED display
Best For: Tiny point-of-use installs that need basic warm water
Whole-Home Smart Pick – Westinghouse 7.9 GPM Gas Indoor
If you’re comparing tankless water heaters with leak detection for a whole-house setup, this Westinghouse model stands out for capacity and smart monitoring. It delivers up to 7.9 GPM and 180,000 BTU, making it a strong fit for larger homes that need hot water for multiple fixtures at once, while built-in WiFi keeps you updated on operating status and fault alerts.
Best For: Larger homes that want a high-flow indoor gas tankless heater with app-based monitoring and fault alerts.
Pros:
- Up to 7.9 GPM and 180,000 BTU for whole-home use.
- Built-in WiFi app control with remote fault alerts.
- Self-modulating design helps hold temperature within ±1°F.
- Low activation flow of 0.53 GPM and operation down to 15 PSI.
Cons:
- Requires natural gas, 120V power, and standard 3/4" NPT plumbing.
- Indoor installation only.
For buyers prioritizing capacity and connected alerts, this Westinghouse is a practical whole-home option. It combines steady output, remote monitoring, and energy-saving on-demand heating in a format that suits everyday family use.
Compact Safety Choice – ORBEK 14kW Electric 240V
For shoppers comparing tankless water heaters with leak detection, this ORBEK electric model is notable because it includes leakage protection along with dry-heating and over-temperature safeguards. It’s built for point-of-use comfort, delivering up to 3.38 GPM and stable temperature control in a compact housing that fits tight installation spaces.
Best For: Small-to-medium households that want a compact electric tankless heater with leakage protection and fast hot water.
Pros:
- Leakage, over-temperature, and dry-heating protection included.
- Up to 3.38 GPM for 2-3 points of use.
- Stable temperature control within 1°F.
- Compact design saves more than 50% of space versus tank heaters.
Cons:
- Requires a 240V/60A two-pole breaker and 150A total panel capacity.
- Hardwired installation and 6 AWG wire are required.
This is a strong fit if you want electric efficiency, built-in leak protection, and a slim footprint. Just make sure your electrical service can support the installation requirements before buying.
Portable Outdoor Option – 8L Propane RV Heater
If your search for tankless water heaters with leak detection is focused on portable use, this propane unit is designed for camping, RV travel, and outdoor washing. It delivers 2.11 GPM with a 40,824 BTU output and includes leak detection alongside multiple safety protections for travel-friendly use.
Best For: Campers, RV owners, and outdoor users who want a portable propane heater with leak detection.
Pros:
- Leak detection plus six total safety protections.
- Portable design for camping, RVs, pet washing, and outdoor showers.
- 2.11 GPM flow and 40,824 BTU output.
- Lightweight build is easy to carry and store.
Cons:
- Maximum temperature is limited to 113°F.
- Best suited to outdoor and portable applications rather than whole-home use.
This model makes sense when portability matters more than whole-house capacity. The combination of leak detection, anti-freezing protection, and compact size makes it appealing for trips and outdoor setups.
High-Output Electric Pick – Rheem 18kW 240V Gray
Among tankless water heaters with leak detection, this Rheem stands out more for output and control than for extra smart features. It offers up to 4.4 GPM, a digital thermostatic control with LED display, and self-modulation for consistent performance in a whole-home electric setup.
Best For: Buyers who want a high-output electric tankless heater with precise temperature control.
Pros:
- Up to 4.4 GPM for whole-home hot water needs.
- External digital thermostatic control with LED display.
- Self-modulation helps match output to demand.
- Durable copper immersion heating elements are field serviceable.
Cons:
- No leak detection feature is listed in the supplied notes.
- Requires 240V electrical service and hardwired installation.
This Rheem is a strong choice if you want a proven, high-efficiency electric tankless heater with solid temperature control. It’s best for buyers who prioritize performance and simplicity over extra monitoring features.
Best for Easy Setup – Propane Tankless 14L 3.66 GPM
If you want tankless water heaters with leak detection for camping, RV trips, or other outdoor setups, this propane model focuses on portability and fast hot water. It delivers up to 3.66 GPM with 85,300 BTU output, while its safety list includes leak detection along with overheat, dry-combustion, antifreeze, low-flow, flame-fault, and high-water-pressure protection.
Best For: Campers, RV owners, and outdoor users who want a compact propane heater with built-in leak detection and multiple safety protections.
Pros:
- Built-in leak detection plus six total safety protections
- Portable, compact design for RVs, trailers, and outdoor use
- Strong 85,300 BTU output with up to 3.66 GPM flow
- Wide operating pressure range helps with varied outdoor water supplies
Cons:
- Designed for outdoor use rather than standard indoor installation
- Temperature range tops out at 113°F
- Performance depends on proper water pressure for ignition
This is a practical fit if your priority is a lightweight propane unit that brings leak detection and broad protection into a travel-friendly package. It is less about whole-home coverage and more about dependable hot water on the go.
Smart Electric Pick – Westinghouse 14kW WiFi Tankless
For shoppers comparing tankless water heaters with leak detection in a modern home setup, this Westinghouse electric unit stands out for its ETL-certified safety package and smart controls. It offers 3-second hot water, WiFi/app control, Alexa and Google Home compatibility, and a 4-layer protection system that includes leakage protection.
Best For: Apartments, bathrooms, and small-home installations where smart control and leakage protection matter.
Pros:
- Leakage protection included in a 4-layer safety system
- WiFi, app, Alexa, and Google Home compatibility
- Compact wall-mount design saves floor space
- Fast 3-second heating with up to 3.4 GPM in ideal conditions
Cons:
- Requires a dedicated 60A double-pole breaker and 6 AWG wire
- Best suited to smaller, point-of-use style applications
- Electric installation may be more demanding than a simple plug-in unit
Overall, this is a strong option if you want leakage protection plus smart-home convenience in a compact electric package. It is built more for efficient residential use than for high-capacity whole-house demand.
Whole-Home Gas Pick – Rheem RTG 7.0 GPM Indoor
If you need tankless water heaters with leak detection for a larger indoor installation, this Rheem natural gas model is built around whole-house capacity and protection. It delivers 7.0 GPM, 160,000 BTU output, and LeakGuard leak detection and prevention to help protect against internal water damage.
Best For: Larger families and multi-bathroom homes that want a high-flow indoor gas heater with leak protection.
Pros:
- LeakGuard leak detection and prevention helps guard against water damage
- High 7.0 GPM flow supports 2-3 simultaneous showers
- 160,000 BTU output suits whole-house residential use
- Digital LED temperature control with ±1°F adjustments
Cons:
- Requires indoor natural gas installation with direct venting
- Non-condensing design is less efficient than condensing models
- Size and setup are better suited to permanent home installation
This Rheem is the most whole-house-focused option in the group, with leak detection adding an extra layer of peace of mind. It makes the most sense if you want strong flow, indoor installation, and a system designed for everyday family demand.
Compact Point-of-Use Heater – ThermoMate 4.5kW Under-Sink Heater
If you want tankless water heaters with leak detection for a compact sink setup, this ThermoMate model is built for fast point-of-use hot water rather than whole-home coverage. Its 4.5kW, 120V design is aimed at under- or over-sink installations, with self-modulating output, a digital temperature display, and a tight footprint that fits where space is limited.
Best For: Small kitchens, bars, salons, and other single-sink locations that need instant hot water in a compact electric unit.
Pros:
- 4.5kW electric heating delivers hot water in seconds for one sink
- Self-modulating operation helps use only the energy needed
- Compact body and pre-wired pigtail support space-saving installation
- Cast aluminum heating element and stainless steel water tube are built for durability
Cons:
- No leak detection feature is listed in the supplied product details
- 120V hardwired setup requires a 40A double pole breaker and proper wiring
- Designed for point-of-use applications, not multi-fixture or whole-home demand
This is a practical choice when you need a small, efficient sink heater and can work within its electrical and flow limits. It is less about whole-house capacity and more about delivering reliable hot water right where you need it.
High-Capacity Safety Pick – Rheem RTG 8.4 GPM LP Indoor Heater
For buyers comparing tankless water heaters with leak detection for larger homes, this Rheem indoor propane unit is the strongest capacity option in the group. It delivers up to 8.4 GPM at a 35°F rise, uses a non-condensing direct vent design, and adds a built-in leak detection feature alongside freeze and flame-failure protection.
Best For: Larger households that want continuous hot water for multiple fixtures and value added safety monitoring.
Pros:
- 8.4 GPM output supports 3-4 simultaneous showers
- Built-in leak detection adds an extra safety layer
- Digital LED control allows precise ±1°F temperature adjustment
- Freeze protection and flame failure protection are included
Cons:
- Professional installation is required for indoor use
- It is a liquid propane model, so it is not the right fit for every home
- Larger, wall-mounted gas unit is less suitable for tight point-of-use spaces
This Rheem model is the most complete match if you need whole-house hot water and want leak detection built into the package. Its strength is capacity and safety, not compact size.
Smallest Leak-Protection Pick – Mini 3kW Plug-In Under-Sink Heater
If you’re shopping for tankless water heaters with leak detection around a simple under-sink setup, this mini 3kW model is a lightweight point-of-use option focused on basic warm-water delivery. It plugs into 120V power, uses a control knob for easy adjustment, and includes multiple safety protections such as leakage protection, overheat protection, and dry-heating protection.
Best For: Low-flow sinks in apartments, offices, laundry areas, dorms, or garages where compact size matters most.
Pros:
- Plug-in 120V design makes it easy to place in small spaces
- Includes leakage protection along with overheat and dry-heating protection
- Simple control knob and LED display make temperature adjustment straightforward
- Compact 7.1″ x 9.8″ x 2.8″ footprint fits tight installations
Cons:
- Only 3kW, so it is intended for low-flow use only
- Not suitable for showers or multiple taps at once
- Water temperature depends heavily on flow rate and inlet water temperature
This is the most modest option here, but it does bring leak protection and a very small footprint. It makes sense when you need a simple sink heater rather than higher-output hot water service.
How We Picked These Tankless Water Heaters with Leak Detection
We looked for models that combine dependable hot-water output with practical safety and control features. Priority went to units with leak detection or leak-aware protection, strong temperature control, clear displays, efficient operation, and fit-for-purpose sizing for whole-home or point-of-use use.
We also considered fuel type, flow rate, electrical load, installation flexibility, and whether a model is better suited to a bathroom, kitchen, or full household.
Quick Comparison
Gas models in this group generally offer higher flow rates and are better for multiple fixtures. Electric units are often simpler to place and maintain, but they may be best for smaller homes, apartments, or single-bathroom setups. Under-sink units are the most compact and work well for targeted hot water at one fixture.
Key Buying Factors for Tankless Water Heaters with Leak Detection
Flow Rate and Household Demand
Match gallons per minute to how many fixtures may run at once. A low-GPM unit can work for one sink or shower, while larger homes usually need a higher-output gas model.
Fuel Type and Power Requirements
Natural gas and propane units often deliver the strongest performance, but they need proper venting and gas supply. Electric models avoid venting, yet they require adequate electrical capacity and may need dedicated circuits.
Leak Detection and Safety Features
Look for leak sensors, automatic shutoff protection, freeze protection, overheat protection, and dry-burn safeguards. These features can reduce damage and improve peace of mind, especially in utility rooms, basements, or under-sink installs.
Temperature Control and Convenience
Digital controls, Wi-Fi, and easy-to-read displays make it simpler to dial in stable temperatures and monitor the unit. That matters for comfort, but also for avoiding unnecessary energy use.
Who Should Buy Which Tankless Water Heaters with Leak Detection?
Choose a high-output gas model if you need whole-home hot water for multiple fixtures. Choose an electric mid-range model if you want a simpler install and have moderate demand. Choose an under-sink or mini unit if you only need hot water at one point of use. For best results, pair your choice with professional installation and confirm local code requirements before buying.