For quick, endless hot water, choose a tankless water heater that includes a built-in recirculation pump. This guide compares five top options, clarifying who each unit suits best and why it stands out. Ideal buyers include new home builders, remodelers seeking energy efficiency, and households aiming to minimize wait times for hot water at multiple fixtures.
Overview Of Top Picks
- Rinnai RXP160iN Condensing Smart Sense Tankless Water Heater – 9 GPM, built-in recirculation, versatile indoor/outdoor install
- Watts H2O 0955805 Recirculation System – programmable timer, compatible with existing setups, reduces wait time
- Rheem IKONIC 10.1 GPM Tankless Water Heater – indoor install, recirculation, wifi connectivity
- MIZUDO Natural Gas Tankless Water Heater – high flow, app control, broad temperature range
- HBS24-12 Smart Instant Hot Water Recirculating Pump System – standalone recirc pump compatible with tanked or tankless systems
| Product | Best For | Main Benefit |
|---|---|---|
| Rinnai RXP160iN | Homes needing compact, versatile install | Built-in recirc, high efficiency |
| Watts H2O 0955805 | DIY installers, single-family homes without a return line | Instant hot water with easy installation |
| Rheem IKONIC | Whole-house hot water with smart controls | Recirculation plus EcoNet Wi‑Fi |
| MIZUDO Gas Tankless | Large households needing high flow | High GPM with WiFi app control |
| HBS24-12 Recirculating Pump | Existing tanked or tankless setups needing instant hot water | Quiet, NSF-certified recirc pump kit |
Rinnai RXP160iN Condensing Smart Sense Tankless Water Heater
The Rinnai RXP160iN combines a compact footprint with built-in recirculation, delivering up to 9 GPM. It supports indoor or outdoor installation using Versa Vent and can run on either natural gas or propane. This model emphasizes modern controls and quick flush maintenance. Best for homes needing reliable, space-saving hot water with flexible fuel options.
Who it’s best for: Buyers wanting a compact, versatile unit with integrated recirculation and strong energy efficiency. Why selected: It maintains steady hot water without a separate pump, reducing wait times across multiple fixtures. Caution: Outdoor use requires the RX-OVC vent cap for proper installation.
Watts H2O 0955805 Recirculation System
This system uses thermal bypass technology to provide instant hot water at faucets or showers. It operates on 120V and is designed for easy DIY installation without a return line. It includes a pump, sensors, valves, and supply lines. Best for: homes seeking immediate hot water without modifying existing plumbing extensively.
Who it’s best for: DIY homeowners and remodel projects needing a quick, energy-saving recirculation upgrade. Why selected: It eliminates wait times and can significantly reduce water waste. Caution: Not designed for tankless water heaters, so proper compatibility checks are essential before pairing with a tankless unit.
Rheem IKONIC 10.1 GPM Natural Gas Tankless Water Heater
The IKONIC series provides continuous hot water with a built-in recirculation option, supporting whole-house needs with 180,000 BTU input. It features EcoNet Wi‑Fi technology to monitor usage and adjust settings remotely. Best for: households that value remote control and energy management. Why selected: It combines powerful on-demand performance with smart connectivity for ongoing efficiency. Caution: Verify electrical and venting requirements during installation.
MIZUDO Natural Gas Tankless Water Heater
With 199,000 BTU input, this unit supports up to 10.3 GPM, suitable for busy households with multiple fixtures. It offers precise temperature control from 95–149°F and app-enabled controls. Best for: large homes needing strong simultaneous hot water across several outlets. Why selected: High flow and precise modulation enhance comfort during peak usage. Caution: Higher BTU models require adequate venting and gas supply capacity.
HBS24-12 Smart Instant Hot Water Recirculating Pump System
This pump system is NSF-certified and designed for quiet operation. It features dual temperature sensors and supports multiple remote controls. Best for: retrofits or upgrades to existing tanked or tankless setups requiring reliable hot water recirculation. Why selected: It enhances comfort with precise temp control and a built-in check valve to prevent backflow. Caution: It is a pump kit, not a full water heater unit, so pairing with a compatible heater is essential.
Buying Guide: Key Considerations For Choosing A Tankless Water Heater With Built-In Recirculation
- Flow rate needs: Calculate total GPM at peak usage to ensure the unit’s GPM rating covers multiple fixtures simultaneously.
- Vent and installation: Indoor vs. outdoor installation options require proper venting and clearances. Check for required vent caps and compatibility with existing vent systems.
- Fuel type and efficiency: Natural gas vs. propane affects efficiency and fuel costs. Look for high UEF and condensing designs for better energy savings.
- Integrated vs. add-on recirc: Built-in recirculation simplifies installation; add-on pumps require separate integration with the heater’s plumbing.
- Smart connectivity: Wi‑Fi or app control can help monitor temperatures, maintenance, and energy use. Consider whether remote control is a priority.
- Installation complexity: Some models are easier for DIY installation; others may require professional service for gas venting and wiring.
- Maintenance needs: Quick access to flushing features and cleaning ports reduces long-term upkeep time.
- Warranty and service availability: Check for local service options and warranty terms to protect investment.
FAQ
- What is a tankless water heater with built-in recirculation?
It’s a water heater that heats water on demand and includes a recirculation pump inside the unit or as part of the system, reducing wait times for hot water. - Do I need a return line for recirculation?
Some systems avoid needing a return line, while others rely on a dedicated return loop. Confirm compatibility with your home plumbing. - Can I install these myself?
Many components are DIY-friendly for simple upgrades, but gas venting and electrical connections often require a licensed technician. - Which gas type is more cost-effective?
Natural gas generally offers lower operating costs in many regions, but availability and price vary by location. - Is Wi‑Fi control worth it?
Wi‑Fi control helps with scheduling, alerts, and remote adjustments, which can improve daily usage and maintenance planning. - What should I consider before buying?
Evaluate space, flow needs, venting requirements, energy efficiency, and whether you want integrated or add-on recirc.