For most homes, the best recirculating pump for tankless water heater use is Product 3 because it installs without a dedicated return line and includes a programmable timer. That matters: a pump can save water, but the wrong setup can also waste heat and run all day like it’s earning overtime.
What to remember
Pick Product 3 if you want a pump that works without a dedicated return line.
Choose a built-in recirculating tankless heater if you’re replacing the whole unit and want one less add-on.
Check whether the system needs a return line, a crossover valve, or only a timer.
A pump that runs too long can erase part of the water savings with extra heat loss.
Indoor tankless and pump setups still need the installation and venting the heater manual calls for.
A tankless unit with recirculation gives you hot water faster, but the right buy depends on plumbing layout, control method, and whether your heater already supports recirc.
If your house has no return line, start with a pump that can work at the heater or under the farthest fixture. If your tankless model already has built-in recirculation, a pump may be the wrong fix altogether.
Recirculating Pump Comparison for Tankless Water Heaters
Best Recirculating Pump for Tankless Water Heater Picks
#1Best Retrofit
A. O. Smith APCOM TV1 Recirculating Pump
Best for Homes without a dedicated return line needing simple, efficient recirculation
The APCOM TV1 installs directly at the water heater and works without a dedicated return line, making it ideal for retrofits. Its built-in programmable timer cuts run time and energy waste, helping save water and reduce costs. The kit includes everything needed for a straightforward installation, though professional plumbing help is recommended if cutting into pipes.
Type Pump kitControls Built-in programmable timerReturn line NoFlow rate —
Why it made the cut
Installs without a return line
Includes a programmable timer for energy savings
Complete kit with pump, bypass valve, fittings
Good to know
Requires professional installation if pipes must be cut
Limited to indoor use only
No Wi-Fi or smart home integration
Skip it if Skip this if your home has a dedicated return line or you want a fully integrated water heater and recirculation system.
Rheem Prestige RTGH-RH11DVLN Tankless Water Heater
Best for Compact tankless replacement with smart recirculation and leak detection
This Rheem model combines a compact tankless heater with built-in recirculation that learns your water use patterns to optimize run times. It includes water and gas leak detection that shuts down the unit for safety. Its space-saving design fits well for replacing older tanks while improving efficiency.
Type Tankless water heater with recirculationControls Auto-learn programmingReturn line —Flow rate 11.0 GPM
Why it made the cut
Auto-learn recirculation timing
Water and gas leak detection
Compact footprint for easy replacement
Good to know
Requires professional installation
No Wi-Fi control
Recirculation tied to the water heater, not a separate pump
Skip it if Skip if you want a standalone recirculating pump or Wi-Fi app control.
Best for Whole-house instant hot water with customizable recirculation and remote control
The Rheem IKONIC is a super high efficiency tankless gas water heater with a built-in recirculation system controlled via Wi-Fi. You can customize temperature and recirculation settings from your phone. Its hot-start programming avoids cold water bursts by keeping water ready during back-to-back use, ideal for busy households.
Type Tankless water heater with built-in recirculationControls Wi-Fi appReturn line —Flow rate 11.2 GPMBTU input 199,900
Best for Energy-conscious users wanting quiet operation and multiple modes
This PROZRTED pump offers three running modes including smart and energy-saving settings, plus a built-in thermostat to maintain water temperature. Its 24V brushless motor runs quietly and efficiently. NSF certification ensures it meets health and safety standards, making it a solid choice for users who want control and quiet performance.
Type Recirculating pumpControls Three modes, built-in thermostatReturn line —Flow rate 6.1 GPM
Why it made the cut
Three operating modes for energy savings
Quiet brushless motor
NSF certified for safety
Good to know
Smaller flow rate compared to tankless heaters
Requires power supply compatibility
Limited to indoor use
Skip it if Skip if you want a pump without multiple modes or certification.
Best for Users wanting remote control and flexible speed for tanked or tankless systems
The PROZRTED HBS24-12Z adds Wi-Fi plug compatibility for remote operation and three adjustable speeds. It supports smart memory to retain settings after power loss and includes two temperature sensors for precise comfort. This pump is NSF certified and works with both tanked and tankless heaters, offering versatile control for energy savings.
Type Recirculating pump systemControls Wi-Fi compatible, three speedsReturn line —Flow rate —
Why it made the cut
Wi-Fi compatible for remote control
Three speed settings with smart memory
NSF certified for health and safety
Good to know
Requires compatible smart plugs
Installation complexity higher than basic pumps
Not designed for outdoor use
Skip it if Skip if you don’t need Wi-Fi control or multiple speed settings.
The best recirculating pump for a tankless water heater is one that installs without a dedicated return line and includes a timer or on-demand control, like the APCOM TV1 Instant Hot Water Recirculating Pump. A tankless water heater recirculating pump moves hot water through your home’s plumbing so the pipes are warm before you open the tap, cutting wait time and water waste.
Not all recirculating pumps are made equal for tankless models. The key isn’t raw flow rate but how the pump manages operation. A programmable timer or demand sensor ensures it runs only when needed, saving energy and preventing heat loss from constant circulation.
Pump Feature
Why It Matters
No dedicated return line needed
Easier retrofit for existing homes without extra plumbing
Programmable timer or on-demand control
Prevents unnecessary run time and energy waste
Flow rate around 1-2 GPM
Sufficient to keep lines warm without overloading the heater
Recirculating Pump Features Important for Tankless Water Heaters
Myth
Any recirculating pump works fine with any tankless water heater
Fact
Tankless water heaters require pumps designed for on-demand operation. Continuous-flow pumps can cause heat loss or force the heater to cycle unnecessarily, increasing wear and energy use.
What does a recirculating pump do on a tankless water heater? It keeps hot water moving through your pipes on a schedule or when triggered. That means hot water arrives at the faucet almost instantly, without running the tap for a minute or more.
In short
A tankless water heater recirculating pump with timer or on-demand control like the APCOM TV1 is the best first buy for most retrofits. It saves water, energy, and hassle without rewiring your plumbing.
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How To Choose A Tankless Recirculating Pump
A recirculating pump for a tankless water heater moves hot water through your pipes so you don’t wait for it at the tap. Unlike traditional heaters with a storage tank, tankless units heat water on demand, so the pump must be compatible with this setup to avoid damage or inefficiency.
You can’t just use a regular recirculating pump designed for tank-style heaters. Tankless water heaters need pumps that either work without a dedicated return line or are built to handle on-demand heating cycles. Using the wrong pump wastes energy and stresses your system.
Look first for pumps designed specifically for tankless models. Many, like the APCOM TV1, work with your existing cold water line as the return path, eliminating the need for extra plumbing. Others integrate controls or sensors to match the heater’s flow and temperature patterns.
Control features matter more than raw power measured in gallons per minute (GPM). A high GPM pump won’t save water if it runs nonstop or at the wrong times. Programmable timers, smart modes that respond to your usage, or manual on-demand buttons let you tailor operation to your household schedule.
Materials and certifications affect safety and durability. Pumps with copper or stainless steel wetted parts resist corrosion better than plastic, especially if they contact potable water. NSF or UL certifications assure you the pump meets health and electrical standards.
An integrated recirculating pump built into the tankless water heater itself is designed for perfect timing and flow. It avoids extra installation and often syncs directly with the heater’s controls. However, these models tend to cost more and may not suit every plumbing layout.
Before You Buy
Confirm the pump is compatible with tankless water heaters
Check if your plumbing has a dedicated return line or if the pump works without one
Look for programmable or smart controls to avoid waste
Verify materials are corrosion-resistant and safe for drinking water
Decide if you want a separate pump or integrated recirculation in the heater
Why GPM Isn’t Everything
A pump’s GPM rating tells the maximum flow it can handle, but placement and control logic decide how effectively it delivers hot water. A smaller pump with smart timing can outperform a larger pump that runs constantly and wastes energy.
Good for tankless water heaters
Designed for on-demand heating cycles
Works without dedicated return line options
Programmable or smart controls reduce waste
Not for tank-style heaters
May require specific plumbing setups
Integrated pumps are more expensive
Wrong pump can cause overheating or short cycling
How Long A 20 Lb Tank Lasts Is The Wrong Question Here
The runtime of a 20 lb propane tank doesn’t tell you much about saving water or energy with a hot water recirculating pump for tankless systems. The pump’s electrical draw is low, often under 30 watts, but the real cost is in heat lost by keeping pipes warm too long.
Say your pump draws 25 W and runs 4 hours a day on a timer to cover morning and evening use. That’s 0.025 kW × 4 h = 0.1 kWh daily. At 17 cents per kWh, it costs about 1.7 cents a day, or around 50 cents a month just to run the pump motor.
Heater
Watts
Per hour
Per day (4 h)
Per month (30 days)
Pump power draw
25 W
0.4¢
1.7¢
51¢
Calculated at 17¢ per kWh. Electricity cost for running a small recirculating pump on a timer
The catch is the heat loss from hot water sitting in the pipes while the pump runs or when the line stays warm between cycles. This lost heat can add up to several therms or more of gas per month, depending on pipe length, insulation, and water temperature settings.
If your tankless water heater already includes a built-in recirculation pump, the controller’s programming often matters more than adding another pump. Smart timers or demand sensors can cut run time and heat loss far better than a simple on/off switch.
House with Distant Bathroom
Imagine a house where the farthest bathroom is 60 feet from the tankless heater, across the kitchen and living room. A pump that runs too long wastes heat, but too short a run means waiting for hot water. A timer or demand system that matches actual use patterns saves both water and energy.
A tankless hot water heater recirculating pump designed for this use balances low power draw with control options that keep the lines warm only when needed. That’s more important than obsessing over how long a 20 lb tank lasts.
Safety And Certification For Recirculating Pump Systems
A tankless water heater can work with recirculating pumps or valves, but safety and code compliance depend on proper installation. Always follow the manufacturer’s instructions for venting, combustion air, and clearance around the heater.
Not every recirculating system requires a dedicated return line. Some use a crossover valve at the fixture to send cooled water back to the heater, cutting plumbing costs but requiring the right valve and pump specs.
Before Installing a Recirculating Pump System
Confirm the pump is certified for potable water contact.
Verify compatibility with your tankless water heater model and manual.
Ensure venting and combustion air meet local code and manufacturer requirements.
Check if a dedicated recirculating line is needed or a crossover valve can be used.
Hire a licensed professional for gas connections, venting modifications, and condensate management.
Carbon Monoxide Risk
Improper venting or combustion air can cause dangerous carbon monoxide buildup. Never skip manufacturer instructions or local codes on venting and installation.
Recirculating Line Not Always Required
Some tankless systems with built-in recirculation pumps can operate efficiently using a crossover valve to return cooled water. This setup avoids installing a separate return line but needs careful valve selection and control logic.
If your tankless water heater has a recirculating pump, you may not need a dedicated recirculating line to the furthest bathroom. The system’s design and the plumbing layout determine what’s best, so consult the manual and pros before planning.
What Competitors Leave Out About Built-In Recirculation
A Rheem recirculating tankless water heater or any tankless hot water heater with recirculation pump combines the heater and pump in one system, offering advantages that add-on pumps can’t match.
Does a recirculating pump work with a tankless water heater? Yes, but built-in recirculation in models like the Rheem IKONIC 11.2 GPM (Product 1) and the Rheem Prestige Condensing (Product 2) provides a cleaner, more integrated setup than retrofitting an add-on pump.
These integrated units include Wi-Fi control, auto-learn programming to match your usage patterns, leak detection, and hot-start behavior that prevents cold water bursts. Retrofits often lack these features or require complex wiring and extra hardware, which can clutter utility closets and raise installation costs.
Good for
Whole-house upgrades replacing an old tankless heater
Tight utility spaces where plumbing changes are limited
Users wanting smart control and leak alerts built-in
Not for
Homes with a functioning tankless heater needing only occasional recirculation
Budget-conscious buyers avoiding full replacement costs
A simple rule: if your tankless water heater is near the end of its life, compare the full installed cost of a new unit with built-in recirculation against adding a pump to your existing heater. Installation labor often tips the scales.
Feature
Add-On Pump
Built-In Recirculation
Installation complexity
Moderate to high, plumbing retrofit needed
Simpler with factory integration
Smart controls
Usually limited or separate apps
Included with auto-learn and Wi-Fi
Leak detection
Rare, aftermarket add-ons
Standard on newer models
Space requirements
Extra components mean more clutter
Compact, all-in-one design
Startup behavior
Cold water burst common
Hot-start prevents cold water flush
How built-in recirculation compares to add-on pumps
In short
Built-in recirculation in tankless heaters is worth it for replacement jobs or whole-house upgrades. Add-on pumps suit fixes and small tweaks. Always check total cost, not just pump price.
Questions People Ask
What is a recirculating pump for a tankless water heater?
A recirculating pump moves hot water through your plumbing so you get hot water at the tap instantly. It reduces water waste by keeping hot water ready in the pipes, which is especially useful for tankless water heaters that heat water on demand but can take time to deliver hot water to distant fixtures.
Does a recirculating pump work with a tankless water heater?
Yes, recirculating pumps can work with tankless water heaters, but the system needs proper controls to avoid continuous running. Pumps with timers or on-demand activation prevent heat loss and unnecessary energy use, making them a good match for tankless units when installed correctly.
Can you use a regular recirc pump with a tankless heater?
Regular recirculating pumps designed for tank-style heaters often run continuously and require a dedicated return line, which isn’t ideal for tankless systems. Tankless-compatible pumps usually include timers or sensors to run only when needed and can work without a return line, saving energy and installation complexity.
Do you need a return line when using a tankless water heater with a recirculating pump?
Not always. Some pumps designed for tankless water heaters operate without a dedicated return line by routing water back through the cold line or using a valve at the fixture. This setup reduces plumbing costs and simplifies retrofit installations.
What is an integrated recirculating pump on a tankless water heater for?
An integrated recirculating pump is built into the tankless water heater to provide instant hot water without separate pump installation. It’s designed to optimize flow and temperature control, improving convenience and efficiency while reducing the risk of improper pump sizing or installation.
How do I choose the correct recirculating pump for a tankless water heater?
Choose a pump that matches your system’s plumbing layout and includes a timer or on-demand control to avoid running constantly. Pumps without a dedicated return line are easier to install in existing homes. Also consider pump flow rate and compatibility with your water heater’s specifications.
Can you have a recirculating line from a tankless water heater?
Yes, a recirculating line can be installed with a tankless water heater to keep hot water circulating near fixtures. This requires careful design to prevent heat loss and ensure the pump cycles properly, often using timers or sensors to run only when hot water is needed.
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