Answering the question “which hot water heating system should I choose?” this guide highlights five practical options for American buyers. Each product is chosen for reliability, practicality, and ease of use in homes, apartments, RVs, or compact spaces. The top picks cover traditional RV-style tank heaters, compact electric tankless options, gas-powered tankless models, a recirculation system, and a versatile all-around pick. Whether you need steady residential-style hot water, space-saving on-demand heating, or reduced water waste, there is a clear choice for different lifestyles and setups.
Summary table of chosen products:
- Suburban SW6DE 6-Gallon RV Water Heater – Best for RV travelers and small mobile setups.
- 110V Tankless Electric Heater (3,000W, under-sink) – Best for apartments or small kitchens/bathrooms needing instant hot water.
- Second 110V Tankless Electric Heater (3,000W, under-sink) – Similar use-case with compact wall-mount design; choose for multiple under-sink spots.
- MIZUDO 120,000 BTU Gas Tankless – Best for whole-house use with flexible indoor/outdoor installation.
- Watts Heat H2O Recirculation System – Best for reducing wait time and water waste in existing homes.
Suburban SW6DE 6-Gallon RV Water Heater
This 6-gallon Suburban tank is designed for durability in RVs and mobile setups, combining a porcelain-lined steel tank with an optional electric element for campsite or generator power. It uses a replaceable anode rod that doubles as a drain, improving maintenance access and extending life. This is best for RV owners who want reliable hot water on the road and the flexibility to heat water without always relying on a generator.
Best for: RV travelers or small mobile living spaces seeking a compact, durable heating option with optional electric heating.
Why selected: The porcelain-lined tank and replaceable anode provide corrosion protection, while the dual heating approaches (gas and optional electric) offer versatility at a reasonable size for limited spaces.
Caution: Ensure compatibility with your RV’s electrical supply when using the electric element; installation and venting requirements vary by model and vehicle.
110V Tankless Electric Heater, 3000W (Under Sink)
This compact tankless electric heater provides instant hot water with a 3000W power rating and a precise temperature range. It features an LED display and supports Celsius/Fahrenheit settings. Built with stainless steel and ABS, it’s designed for narrow spaces like under sinks, apartments, or RV kitchens. Its high energy efficiency and safety protections support reliable performance with minimal wasted energy.
Best for: Apartments, small kitchens, or bathrooms needing instant, on-demand hot water in a tight space.
Why selected: Quick heat-up with no preheating delay and a compact wall-mounted design make it a practical pick for space-constrained homes.
Caution: Verify electrical capacity and ensure proper ventilation in enclosed spaces, as with any under-sink tankless unit.
110V Tankless Electric Heater (Another Under Sink Model)
This second under-sink tankless option uses 3000W to heat water on demand, with the same rapid heating benefits and an LCD display for status. It emphasizes a compact, wall-mounted design suitable for kitchens, bathrooms, RVs, or apartments. Safety features include IPX4 waterproofing and dry-burn protection, making it a dependable substitute where space is at a premium.
Best for: Homes or spaces needing flexible, on-demand hot water with a clear display and strong safety protections.
Why selected: It offers a similar performance profile to the first under-sink model, giving buyers another option in the same category with a compact footprint.
Caution: As with any tankless unit, ensure adequate electrical supply and proper venting or clearance per local codes.
MIZUDO 120,000 BTU Gas Tankless Water Heater
This natural gas tankless unit offers up to 120,000 BTU and a maximum flow of 5.1 GPM, with indoor or outdoor installation versatility. It emphasizes smart WiFi/app control and precise temperature stability within 1°F, making it suitable for whole-house use where steady hot water is required across multiple fixtures. The product is CSA-certified and designed for flexible installation needs.
Best for: Whole-house applications needing reliable, on-demand hot water with remote monitoring and temperature stability.
Why selected: The indoor/outdoor adaptability and WiFi/app control provide modern convenience and flexible placement in varied homes.
Caution: Gas appliances require proper venting, gas line sizing, and professional installation in many jurisdictions.
Watts Heat H2O Recirculation System
This programmable recirculation system uses a thermal bypass approach to deliver hot water at the tap quickly, reducing wait time and water waste. It operates on 120V and includes a pump, sensor valve, and all required hardware for installation under a sink. It’s best for homeowners seeking immediate hot water at fixtures without upgrading their entire water heater.
Best for: Existing homes or remodels aiming to reduce water waste and improve hot-water availability at distant fixtures.
Why selected: The system’s quick response and offline compatibility with standard plumbing make it a practical upgrade for households prioritizing efficiency.
Caution: Not designed for use with tankless water heaters; verify compatibility with your current setup before installation.
Buying Guide
- What space do you have? Tank-style heaters require cabinet or closet space, while tankless units save space but need proper clearance and venting for gas models.
- What’s your energy strategy? Tankless models offer on-demand efficiency but can have higher upfront costs; traditional tanks are simpler to install but may run higher ongoing energy use.
- Power and fuel type: Decide between electric, gas, or dual-powered options. Electric units require adequate circuit capacity; gas units depend on venting and gas supply.
- Usage profile: For RVs or campers, a compact, durable tank model is ideal. For whole-house use, a gas tankless or high-capacity electric tankless system may be preferable.
- Safety and maintenance: Look for automatic shutoff, dry-bire protection, and accessible maintenance features like replaceable anodes or digital controls for temperature management.
- Installation considerations: Some units are ready for simple DIY installs; others require professional installation, especially gas models and high-output electric systems.
FAQ
- What size hot water heater do I need for a small apartment? A compact electric tankless or a small 4–6 gallon tank can typically meet basic needs, depending on how many fixtures are used simultaneously.
- Do tankless water heaters save energy? Yes, on-demand heating reduces standby heat loss, but the overall energy savings depend on usage patterns and proper sizing.
- Is a recirculation system right for me? If you frequently waste water waiting for hot water at distant fixtures, a recirculation system can cut water loss and improve hot-water readiness.
- Can I install a gas tankless water heater myself? Gas units require venting, gas line sizing, and safety considerations; professional installation is typically recommended.
- Will I need a new vent for a tankless heater? Some tankless gas models require venting and proper clearance; check local codes and manufacturer instructions before installation.
- Are electric under-sink heaters suitable for whole-house use? They are typically best for point-of-use needs (single or few fixtures) rather than serving an entire home, unless multiple units are installed or the home has adequate electrical supply.