A gas tankless water heater with a built-in recirculation pump can reduce the wait for hot water at distant faucets while heating water on demand. In this group, the Rinnai RXP199iN and RXP160iN are the only models whose supplied product information confirms an internal pump and intelligent recirculation. The other three are gas tankless options without a confirmed built-in pump, so consider them only if recirculation is not essential or you plan to discuss a separate pump setup with a qualified installer.
Our top pick is the Rinnai RXP199iN for homes that need higher flow capacity and built-in Smart-Circ scheduling. The RXP160iN offers similar recirculation features at a lower stated maximum flow rate. Before choosing either, match the heater’s capacity to your incoming water temperature, household demand, gas supply, venting, and plumbing layout.
Table of Contents
Quick Comparison
| Product | Fuel | Maximum stated flow | Built-in recirculation pump | Best suited for |
|---|---|---|---|---|
| Rinnai RXP199iN Condensing Smart Sense | Natural gas or propane | Up to 11.1 GPM | Yes, with Smart-Circ | Higher-demand homes that want built-in recirculation |
| Rheem RTG Series 7.0 GPM | Natural gas | 7.0 GPM | Not listed in supplied specifications | Homes needing a standard indoor tankless heater |
| Rinnai RXP160iN Condensing Smart Sense | Natural gas or propane | Up to 9 GPM | Yes, with Smart-Circ | Homes wanting built-in recirculation with somewhat lower capacity |
| GASLAND Gasmart E 199,000 BTU | Natural gas | Up to 7.6 GPM | Not listed in supplied specifications | Buyers considering an indoor whole-house unit without confirmed integrated recirculation |
| GASLAND Gasmart C Propane | Propane | Up to 5 GPM | Not listed in supplied specifications | Smaller or lower-demand homes using propane |
Our Picks: Best Gas Tankless Water Heater With Recirculating Pump reviews
Rinnai RXP199iN: Best for Higher Hot-Water Demand
The Rinnai RXP199iN is the strongest match here if you want a gas tankless heater with an integrated recirculation pump and higher stated capacity. It delivers up to 11.1 GPM, according to the supplied description, and uses Smart-Circ technology to learn household hot-water patterns and schedule recirculation. That can help reduce the wait at a tap without requiring you to run water while waiting for it to warm.
This condensing model is rated at 199,000 BTU and a UEF of .98. Its Smart Sense gas control system is listed for natural gas or propane, and the unit can be installed indoors or outdoors with the required RX-OVC vent cap for an outdoor installation. Wi-Fi control requires a separate Control-R module, so it is not included as a built-in feature.
The higher flow rating makes this the most suitable option in this group for households with several simultaneous hot-water needs. Still, maximum GPM is not a promise that every home can run many fixtures at once: actual output depends on the incoming water temperature and the temperature rise your home needs. The unit is compact for its capacity, but its gas, venting, condensate, and recirculation setup should be planned by a qualified professional.
Pros:
- Built-in pump with Smart-Circ scheduling
- Highest stated flow capacity in this group
- Smart Sense system supports natural gas or propane
- Indoor or outdoor installation options, with the required outdoor vent cap
Cons:
- Wi-Fi control requires a separate Control-R module
- Professional installation is recommended, and the recirculation layout needs to suit your plumbing
Verdict: Choose the RXP199iN if you want an integrated recirculation pump and need the most capacity among these picks, provided your home’s gas supply and plumbing can support it.
Rheem RTG Series: A Natural-Gas Option Without Confirmed Built-In Recirculation
The Rheem RTG is an indoor, non-condensing natural-gas tankless heater rated at 160,000 BTU per hour and up to 7.0 GPM at a 35°F temperature rise. Its supplied specifications do not list a built-in recirculation pump, so it is not a direct substitute for either Rinnai model if an integrated pump is a must-have. Ask a qualified installer whether a separate recirculation setup is suitable for your home and this heater.
The unit has a digital temperature control panel with adjustments listed to within ±1°F, plus freeze protection, flame-failure protection, and leak detection and prevention. Its stated UEF is 0.82. Owners have described it as capable of supporting everyday combinations of showers and other hot-water uses, though actual performance depends on household demand and local water conditions. Regular maintenance matters; follow the manufacturer’s flushing and care instructions, especially if your home has hard water.
Compared with the Rinnai picks, the Rheem has a lower stated flow rate and no confirmed integrated recirculation feature. It may still make sense if your priority is a natural-gas indoor tankless unit with safety features and you do not need the pump built in.
Pros:
- Up to 7.0 GPM at a stated 35°F temperature rise
- Digital temperature adjustment and built-in safety features
- Leak detection and prevention are included
- Wall-mounted design helps save floor space
Cons:
- Supplied specifications do not confirm an integrated recirculation pump
- Natural-gas fuel only
Verdict: Consider the Rheem if you want an indoor natural-gas tankless heater and can forgo a built-in recirculation pump or confirm a compatible separate solution with your installer.
Rinnai RXP160iN: Best Built-In Recirculation for Moderate Demand
The RXP160iN gives you the same core idea as the RXP199iN: a condensing gas tankless heater with a built-in pump and Smart-Circ intelligent recirculation. Its scheduling feature learns patterns of hot-water use and adjusts pump operation accordingly. For households that want less waiting at distant fixtures but do not need the RXP199iN’s higher stated capacity, this is the more moderate option.
Rinnai lists this model at 160,000 BTU and up to 9 GPM, with a UEF of .97. It can use natural gas or propane through its Smart Sense gas control system. The product information also describes multiple venting options and recommends professional installation. As with the larger model, Wi-Fi control requires the separately sold Control-R module.
The key buying question is whether 9 GPM is enough for your home at your required temperature rise. The stated maximum does not account for every climate or incoming-water condition, so use a local installer’s sizing calculation rather than choosing by the headline number alone. Its lower capacity may be a better fit for a household with fewer simultaneous hot-water demands, while the RXP199iN is the stronger choice when greater flow is needed.
Pros:
- Built-in recirculation pump with Smart-Circ scheduling
- Up to 9 GPM stated flow and 160,000 BTU output
- Supports natural gas or propane
- Condensing design with a stated UEF of .97
Cons:
- Lower stated flow than the RXP199iN
- Wi-Fi control module is not included
Verdict: Pick the RXP160iN if you want Rinnai’s built-in recirculation features but your home’s calculated hot-water demand does not call for the larger RXP199iN.
GASLAND Gasmart E: A High-Output Indoor Natural-Gas Alternative
The GASLAND Gasmart E is an indoor natural-gas tankless model rated at 199,000 BTU, with a stated maximum flow of up to 7.6 GPM. It is described as CSA certified and includes safety features such as freeze protection, flame-failure protection, and overheat protection. Its compact wall-mounted design may appeal if you are replacing a tank heater and want to free up floor space.
The supplied specifications do not list a built-in recirculation pump or a learning schedule. That is an important distinction for this keyword: this model may provide on-demand hot water, but it is not confirmed as a heater with integrated recirculation. If reducing the wait at distant faucets is your main goal, compare the total cost and compatibility of any proposed separate pump setup with choosing one of the Rinnai models.
GASLAND lists a UEF of 0.8 and describes the unit as having an error-code indicator. While the BTU rating is high, its listed maximum GPM is lower than both Rinnai models, and the real-world flow you get depends on the temperature rise your home needs. Verify venting, gas-line sizing, and local code requirements before purchase.
Pros:
- 199,000 BTU output and up to 7.6 GPM stated flow
- CSA certification and several listed safety protections
- Compact, wall-mounted indoor design
- Error-code indicator is listed among its features
Cons:
- Supplied specifications do not confirm a built-in recirculation pump
- Natural-gas model only
Verdict: The Gasmart E is an option to compare if you want an indoor natural-gas tankless heater, but choose a Rinnai instead if integrated recirculation is a requirement.
GASLAND Gasmart C Propane: A Smaller-Capacity Choice
The GASLAND Gasmart C is an indoor propane model rated at 113,000 BTU and up to 5 GPM. It has a touch-screen display, a water-flow sensor, and smart modulation designed to help maintain a steady set temperature as water demand changes. The listed safety features include freeze protection, an overheat cutoff, temperature sensors, and a flame sensor.
This is the lowest-capacity option in the group, so it is more appropriate for a smaller home or a limited number of simultaneous hot-water uses than for a large household with several showers running at once. Its supplied product information does not list a recirculation pump, so it does not meet the main requirement as directly as either Rinnai. The stated connections are 3/4-inch NPT, and the description says a 3-inch exhaust pipe is required; have an installer verify that the setup suits your home and local requirements.
The propane-only fuel type can make it relevant where natural gas is not available, but make sure the unit is sized for your climate and incoming-water temperature. The supplied description also says the freeze-protection heating feature requires power to remain on. That is worth considering if the unit will be installed where freezing conditions are possible.
Pros:
- Propane fuel may suit homes without a natural-gas connection
- Touch-screen controls and stated temperature-management features
- Multiple listed safety protections, including freeze protection
- Wall-mounted design
Cons:
- Up to 5 GPM is the lowest stated flow in this group
- Supplied specifications do not confirm a built-in recirculation pump
Verdict: Consider the Gasmart C for a smaller, propane-powered setup where its 5 GPM limit fits your demand; it is not the right pick if you need an integrated recirculation pump.
How to Choose a Gas Tankless Water Heater With Recirculating Pump
Confirm the Pump Is Actually Built In
A tankless heater and a recirculation pump solve different parts of the hot-water wait. The heater warms water on demand; the pump moves hot water through the plumbing loop so it is closer to the fixture when you turn on the tap. In this group, only the Rinnai RXP199iN and RXP160iN are specifically described as having an internal pump and Smart-Circ recirculation. Do not assume a model has a pump just because it is tankless or advertises instant hot water.
Size for Temperature Rise, Not Just Maximum GPM
GPM is only useful when considered alongside temperature rise: the difference between the incoming water temperature and the temperature you want at the tap. Colder incoming water means the heater must work harder to deliver the same hot-water flow. Ask an installer to estimate the simultaneous demand in your home and size the unit for your local winter water temperature, rather than relying only on the maximum flow figure in a product description.
Choose the Correct Fuel and Check Gas Capacity
The Rinnai models are listed for natural gas or propane through Smart Sense. The Rheem and GASLAND Gasmart E are listed as natural-gas units, while the GASLAND Gasmart C is a propane model. Fuel compatibility is not the only concern: the existing gas line and supply must also meet the heater’s requirements. Have a qualified professional verify capacity before ordering.
Plan the Recirculation Plumbing
Recirculation depends on the home’s plumbing layout and the heater’s approved installation method. Some systems use a dedicated return line, while other arrangements may use a different manufacturer-approved design. Ask the installer how the pump will work with your existing pipes, how it will be scheduled, and whether the proposed setup is permitted for the exact model. A pump cannot eliminate every wait in every plumbing layout.
Review Venting, Condensate, and Installation Location
Indoor gas heaters need appropriate venting and installation clearances. Condensing models also require planning for condensate drainage. The Rinnai RXP199iN can be installed outdoors only with the specified RX-OVC vent cap, according to its supplied information. Confirm the required vent parts, drainage, and location before buying; do not assume existing tank-heater connections will work unchanged.
Compare Efficiency and Maintenance Needs
The Rinnai RXP199iN and RXP160iN list UEF ratings of .98 and .97. The Rheem RTG lists .82, and the GASLAND Gasmart E lists .8. These figures are useful for comparison, but your actual energy use also depends on household demand, installation, and operating settings. Tankless units need maintenance too. Follow the manufacturer’s instructions for flushing and service, and ask whether your water hardness calls for more frequent care.
Understand Warranty Terms and Professional Setup
Rinnai lists a limited 15-year heat-exchanger warranty and five-year parts and labor coverage, with the labor term depending on registration within 90 days of installation. The Rheem listing gives a one-year labor, 15-year heat-exchanger, and five-year parts warranty. GASLAND describes a one-year replacement promise if the heater stops working within that period. Confirm the full current warranty terms, registration rules, and installation requirements with the manufacturer before purchase. Rinnai recommends professional installation, and gas appliance work should be handled by a qualified technician.
Frequently Asked Questions
Which heater in this list has a built-in recirculation pump?
The supplied product information confirms an internal pump with Smart-Circ intelligent recirculation for the Rinnai RXP199iN and RXP160iN. A built-in pump is not listed for the Rheem or either GASLAND model.
What does a recirculation pump do in a tankless system?
It circulates hot water through a plumbing loop so hot water can be closer to a fixture when you open the tap. The result depends on the plumbing layout, pump settings, and the distance to the fixture; it does not change the heater’s maximum heating capacity.
Is the RXP199iN better than the RXP160iN?
Not for every home. The RXP199iN has a higher stated maximum flow of up to 11.1 GPM, while the RXP160iN is listed at up to 9 GPM. Both have built-in Smart-Circ recirculation. Choose based on a professional sizing estimate of your home’s simultaneous demand and temperature rise.
Can I add a separate recirculation pump to another tankless heater?
Possibly, but compatibility depends on the heater, plumbing arrangement, and controls. The supplied information does not confirm that a separate pump is suitable for the Rheem or GASLAND models here. Ask the manufacturer or a qualified installer to confirm an approved setup before purchasing extra equipment.
Can these heaters run on either natural gas or propane?
The two Rinnai models are described as compatible with natural gas or propane through Smart Sense. The Rheem RTG and GASLAND Gasmart E are listed for natural gas, while the GASLAND Gasmart C is listed for propane. Always match the exact model to your fuel supply.
Does a higher GPM rating guarantee that several showers can run at once?
No. The amount of hot water available depends on incoming-water temperature, required temperature rise, and the combined flow of the fixtures being used. Use the product’s stated rating as a starting point and have a qualified installer size the unit for your home.
Do tankless gas water heaters need regular maintenance?
Yes. Follow the model’s manufacturer instructions for flushing, inspection, and service. Water hardness and local conditions can affect maintenance needs, so ask your installer or manufacturer how often your specific unit should be checked.
Final Recommendation
For a gas tankless water heater with a confirmed built-in recirculation pump, the Rinnai RXP199iN is the strongest choice here for homes that need higher capacity. The Rinnai RXP160iN is the better fit when its lower stated flow is enough for your household. The Rheem and GASLAND units may suit shoppers comparing standard tankless heaters, but their supplied specifications do not confirm integrated recirculation. Before you buy, have a qualified installer check sizing, fuel supply, venting, and the recirculation plan for your home.
