The Best Gas Water Heaters for Today’s Home – Picks from Bob Vila

Quick Look at the Best Gas Water Heaters

Bob Vila’s selections cover the three major residential gas-water-heating formats: storage tanks, tankless units, and combination systems. The original comparison evaluated capacity, efficiency, installation needs, maintenance, construction quality, and household suitability.

Best Gas Water Heater Reviews

Best Overall: Rinnai V65iN Tankless Water Heater

The Rinnai V65iN is a sensible middle ground for homeowners who want on-demand hot water without paying for the most powerful condensing system in the catalog. It is designed for indoor natural-gas installation and can produce up to 6.5 gallons per minute under favorable inlet-water conditions.

That output can be enough for a small or midsize household, particularly when major fixtures are not operated simultaneously. One shower and a kitchen faucet should be a much easier assignment than two showers, a dishwasher, and a washing machine all demanding hot water like impatient customers at a breakfast buffet.

The current manufacturer specification lists a 0.80 UEF, a firing range of 10,300 to 150,000 BTU per hour, Wi-Fi capability, and ultra-low-NOx approval. Its wall-mounted body also returns valuable floor space to the utility room. The principal drawback is installation: converting from a conventional tank may require new venting, gas-line work, electrical service, or plumbing changes.

Runner-Up: A.O. Smith 40-Gallon Natural Gas Water Heater

A traditional 40-gallon gas water heater remains a practical choice for many three- or four-person households. The A.O. Smith model highlighted by Bob Vila pairs familiar tank operation with a 40,000-BTU burner, electronic temperature control, diagnostic indicators, push-button ignition, and a substantial first-hour supply.

The advantage is predictability. A properly sized storage tank can deliver hot water immediately without waiting for a tankless burner to detect flow. It is also often easier to install when replacing another atmospheric gas tank with compatible dimensions and venting.

Efficiency depends on the exact model. Current A.O. Smith 40-gallon atmospheric products can reach a UEF around 0.64 and first-hour ratings near 78 to 80 gallons, while power-vent versions may offer different efficiency and installation characteristics. Buyers should compare the precise model number rather than assuming every 40-gallon cylinder wearing the same logo performs identically.

Best Bang for the Buck: Sure Comfort 40-Gallon Gas Water Heater

The Sure Comfort 40-gallon model appeals to homeowners who need a straightforward replacement rather than a mechanical-room moon landing. Its tall, relatively narrow tank can fit conventional installation spaces, while its burner and first-hour output are appropriate for modest household demand.

It does not offer the highest efficiency, advanced recirculation, or app-based controls. That is not automatically a failure. A simple gas valve, familiar atmospheric vent, and conventional tank can reduce equipment cost and make service easier for technicians accustomed to standard designs.

This option makes the most sense when purchase price matters, the existing vent is in good condition, local codes permit the installation, and the household is unlikely to create extreme simultaneous demand. It becomes less compelling when fuel costs are high or the owner expects to remain in the house long enough for a high-efficiency upgrade to recover its higher initial cost.

Best Tankless: Rinnai RL75iN

With a maximum advertised flow rate of roughly 7.5 GPM, the Rinnai RL75iN offers more capacity than the smaller V65iN. That extra output can be useful in homes where two hot-water fixtures occasionally operate together.

The RL75iN is a non-condensing indoor tankless water heater. It occupies little wall space, modulates its burner to match demand, and avoids the standby heat loss associated with keeping dozens of gallons hot throughout the day. However, maximum GPM is not guaranteed in every house. Colder incoming water requires a larger temperature rise, which reduces the amount of hot water the unit can produce each minute.

Tankless sizing should therefore be based on the required temperature rise and combined fixture flow, not the maximum number printed in large type on a product page. A unit rated for 7.5 GPM in warm conditions may deliver considerably less during a northern winter.

Best Combination Unit: Rheem Prestige Combination Boiler

A combination boiler supplies domestic hot water while also supporting hydronic space heating. This can be an elegant solution for a home that already uses radiators, baseboard heat, or radiant flooring and needs to replace both its boiler and water heater.

The Rheem Prestige model featured by Bob Vila was noted for high efficiency, strong hot-water flow, PVC-compatible exhaust options, and the ability to combine two mechanical functions in one appliance. In the right house, that can free space and reduce the number of separate burners requiring service.

In the wrong house, it can be expensive overkill. A property with a healthy forced-air furnace does not gain much from purchasing a sophisticated combi boiler solely to heat tap water. Installation requires careful load calculations, correct piping, condensate management, combustion setup, and professional commissioning. This is not the weekend to test whether watching three plumbing videos has transformed someone into a boiler engineer.

Best 50-Gallon Model: Rheem Performance Gas Water Heater

A 50-gallon gas water heater is a popular choice for households of three to five people. The Rheem Performance model in Bob Vila’s lineup uses a 38,000-BTU burner and was listed with an 85-gallon first-hour rating, meaning a fully heated tank can supply considerably more than its nominal storage volume during the first hour as the burner heats incoming replacement water.

This distinction is important. Tank capacity tells buyers how much heated water is stored, but first-hour rating provides a better picture of how much hot water the appliance can deliver during a concentrated period of use.

The trade-off is moderate efficiency. A basic atmospheric 50-gallon unit may cost less to buy and install than a condensing or tankless alternative, but it continuously loses some heat through the tank and vent. It is best viewed as a dependable, familiar workhorse rather than the valedictorian of energy conservation.

Best Energy-Efficient Pick: Rinnai RU160iN

The Rinnai RU160iN is a condensing tankless gas water heater designed for homeowners who prioritize energy efficiency, continuous operation, and compact installation. Current specifications list a 0.95 UEF, a maximum flow of 9 GPM, a 15,000-to-160,000-BTU firing range, recirculation capability, ENERGY STAR certification, and Wi-Fi compatibility.

Condensing technology captures additional heat from exhaust gases that a conventional unit would send through the vent. This improves efficiency but introduces condensate that must be drained and, in some installations, neutralized before disposal.

The RU160iN is a particularly strong candidate for efficient new construction or a well-planned renovation. Retrofitting it into an older house may require a larger gas line, new venting, an electrical outlet, drain provisions, and adjustments to the plumbing layout. The heater is compact; the project surrounding it may not be.

How to Choose the Best Gas Water Heater

Choose Between a Tank and Tankless System

A storage water heater keeps a reservoir ready for immediate use. It generally costs less to purchase, fits familiar replacement situations, and can continue operating during an electrical outage if it uses a standing pilot and does not depend on powered controls.

A tankless gas water heater heats water only when a fixture opens. It saves floor space, reduces standby losses, and can provide continuous hot water as long as demand remains within its output capacity. ENERGY STAR notes that certified gas tankless models can save a typical family of four about $95 annually compared with a standard gas storage unit, although actual savings vary by climate, fuel price, usage, installation, and equipment.

Size the Heater for Peak Demand

For a tank model, compare the first-hour rating with the amount of hot water the household uses during its busiest hour. A home with two morning showers, a running dishwasher, and laundry activity needs more than a household where everyone showers at different times.

For tankless models, add the flow rates of fixtures that may operate together and calculate the required temperature rise. A shower might use roughly 1.5 to 2.5 GPM, but fixtures, aerators, and local plumbing vary. Incoming water at 40 degrees Fahrenheit requires much more heating than incoming water at 70 degrees, so climate affects real output.

Understand UEF, FHR, GPM, and BTU

• UEF: Uniform Energy Factor measures energy efficiency within a defined usage category. Higher is generally better when comparing similarly sized and classified heaters.
• FHR: First-Hour Rating estimates how many gallons a storage heater can supply during an hour that begins with a fully heated tank.
• GPM: Gallons per minute describes a tankless heater’s hot-water delivery at a specified temperature rise.
• BTU: British thermal units indicate heating input. More BTUs can support faster recovery or greater flow, but bigger is not automatically better.

Current ENERGY STAR criteria are demanding. Certified gas-fired instantaneous units must have a UEF of at least 0.95 and deliver at least 2.8 GPM over a 67-degree temperature rise. Qualifying residential gas storage heaters must meet efficiency, first-hour, warranty, and safety thresholds.

Check Venting Before Falling in Love With a Model

Atmospheric, direct-vent, power-vent, and condensing appliances have different requirements. Existing chimney venting may not work with a modern high-efficiency system. Likewise, plastic venting suitable for a condensing unit cannot simply be assumed appropriate for every gas appliance.

Installation quotes should include vent materials, combustion-air provisions, gas-line sizing, permits, drain work, electrical connections, removal of the old heater, and any required expansion tank or safety upgrades. The cheapest box can produce the most expensive surprise if the house is not prepared to support it.

Review Local Low-NOx Requirements

Some jurisdictions require low-NOx or ultra-low-NOx gas appliances to reduce nitrogen-oxide emissions. This is particularly relevant in parts of California and other areas with strict air-quality rules. Verify local requirements before ordering because a standard model may not be approved for installation even if it appears physically compatible.

Compare the Complete Installed Cost

Equipment price is only one line of the budget. A direct tank-for-tank replacement can be relatively straightforward, while a tankless conversion may require gas-line enlargement, new vents, electrical work, condensate drainage, relocation of pipes, and wall repair.

Ask installers to provide model numbers and itemized proposals. Comparing one contractor’s basic atmospheric tank against another contractor’s premium condensing package is not a fair comparison, even when both quotes are labeled “new water heater.”

Gas Water Heater Safety and Maintenance

Use Professional Installation

Gas connections, combustion air, exhaust venting, temperature-and-pressure relief piping, seismic restraints, and local permits affect safety. Poor venting can allow carbon monoxide to enter living spaces. The CDC advises that gas appliances be properly vented, while the CPSC recommends regular professional inspection of fuel-burning appliances and functioning carbon-monoxide alarms in the home.

Flush Sediment as Recommended

Minerals and debris can accumulate in storage tanks and tankless heat exchangers. Sediment may reduce heat transfer, create rumbling noises, restrict flow, and increase fuel consumption. Maintenance frequency depends on water hardness, usage, model design, and manufacturer instructions.

Tankless systems in hard-water areas may require periodic descaling with an approved solution. Storage tanks may need flushing and occasional anode-rod inspection. Ignoring maintenance because the heater is hidden in a basement is similar to ignoring dental care because the molars are difficult to see. The eventual surprise is rarely delightful.

Control Water Temperature

Many households use a 120-degree-Fahrenheit delivery temperature to help reduce scald risk and energy use, subject to manufacturer instructions and local code. Homes with special sanitation, medical, recirculation, or storage requirements may use different settings with an approved mixing valve. A qualified plumber can balance comfort, safety, and system design.

Watch for Warning Signs

Call a professional when the heater produces soot, recurring error codes, unusual combustion odors, discolored hot water, popping noises, leaking connections, unstable temperatures, or visible corrosion. A carbon-monoxide alarm requires immediate action according to local emergency guidance; it is not a reminder to add “check heater” to next weekend’s chore list.

Frequently Asked Questions

Is a gas water heater cheaper to operate than an electric model?

It can be, particularly where natural gas prices are low and electricity rates are high. Operating cost depends on local utility prices, heater efficiency, household demand, and maintenance. Compare estimated annual energy costs for specific models rather than relying on a national rule of thumb.

Is a 40-gallon or 50-gallon gas water heater better?

A 40-gallon model may be sufficient for two to four people with moderate, staggered usage. A 50-gallon model provides more reserve for larger families or overlapping showers. First-hour rating is often more useful than tank volume alone.

Can a tankless heater supply two showers?

Yes, provided its output at the home’s required temperature rise exceeds the combined flow of both showers. In cold climates, a larger unit may be needed because the incoming water starts at a lower temperature.

How long does a gas water heater last?

Service life depends on water quality, installation, usage, maintenance, tank protection, and component availability. ENERGY STAR describes tankless units as having an expected life of around 20 years, while conventional tanks generally have shorter service lives. These are planning estimates, not expiration dates engraved by the plumbing universe.

Final Verdict

The best gas water heater is the one that matches the home’s actual demand and installation conditions. The Rinnai V65iN remains an attractive compact option for smaller households, while the Rinnai RU160iN provides a substantial efficiency upgrade for owners prepared to support a condensing tankless installation.

Households that prefer a familiar tank system should consider a properly sized A.O. Smith or Rheem model, paying close attention to first-hour rating, UEF, vent type, warranty, and local emissions rules. The Rheem Prestige combination boiler is the specialized choice for homes that can genuinely benefit from integrated domestic water and hydronic heating.

Do not select a heater by brand name, tank capacity, or advertised GPM alone. Confirm the precise model, calculate peak demand, inspect the existing gas and vent systems, and compare complete installation proposals. That approach is less exciting than buying the shiniest appliance online, but it is considerably more exciting than taking an accidental cold shower in January.

Experience-Based Lessons From Gas Water Heater Ownership

The most common lesson homeowners learn is that installation quality matters as much as the logo on the appliance. Two identical gas water heaters can deliver very different experiences when one has correct gas pressure, carefully designed venting, accessible service valves, and properly supported piping while the other has been squeezed into a corner with all the elegance of a suitcase packed five minutes before a flight.

A straightforward tank replacement often produces the smoothest ownership experience. When the new unit matches the old heater’s fuel, vent type, diameter, height, and connection locations, installation can require fewer modifications. The homeowner receives familiar performance, and local technicians are likely to stock common replacement parts. The downside becomes apparent during heavy use: once the stored hot water is depleted, the household must wait for recovery.

Consider a family of four with a 40-gallon tank. On ordinary weekdays, staggered showers and moderate kitchen use may never challenge the system. When guests arrive and three showers happen before the dishwasher starts, the same heater suddenly appears inadequate. The appliance has not become weaker; the demand pattern has changed. This is why first-hour rating and peak usage deserve more attention than the gallon number printed on the tank.

The tankless experience is different. Owners often love regaining floor space and taking long showers without watching an imaginary fuel gauge. They may be less enthusiastic about the short delay before hot water arrives, the need for periodic descaling, or the installation bill associated with upgrading an undersized gas line. Tankless does not create instant hot water at distant faucets. The water already sitting in the pipe must still travel out before heated water arrives, unless the system includes an appropriately designed recirculation solution.

Another frequent experience involves unrealistic GPM expectations. A homeowner sees a 9-GPM rating and imagines every hot-water fixture operating simultaneously. Then winter arrives, the incoming water becomes much colder, and the heater’s available flow drops because it must add more heat to every gallon. A properly sized unit still performs well, but the headline maximum is not the same as guaranteed winter output.

Maintenance also separates happy long-term owners from people who begin searching for a replacement suspiciously early. In hard-water regions, scale can gradually coat a tankless heat exchanger or collect at the bottom of a storage tank. Performance may decline slowly enough that the household adapts without noticing. Showers become slightly less stable, recovery takes longer, and the burner works harder. Regular flushing or descaling can preserve performance and expose small problems before they grow expensive.

Smart controls are useful, but they should not outweigh core mechanical considerations. Remote temperature adjustment, usage reports, and leak notifications can improve convenience. They cannot compensate for an undersized gas supply, poor venting, insufficient capacity, or nonexistent local service support. A less glamorous model installed correctly by a capable contractor is often a better ownership experience than a feature-packed unit that nearby technicians rarely repair.

The most valuable practical step is obtaining two or three detailed installation proposals that identify the exact model number. Ask why each heater was selected, what peak demand it can support, how venting will be handled, what maintenance it requires, and whether labor is covered after installation. A trustworthy installer should be able to explain the system without turning the conversation into either a chemistry lecture or a mysterious declaration that “this is the one everybody gets.”

Finally, homeowners should think about the next decade rather than only the next invoice. A low-cost tank may be entirely rational for a rental property, a short-term residence, or a simple emergency replacement. A condensing tankless unit may offer better value in a long-term home with high hot-water use and an installation layout that keeps conversion costs reasonable. The best choice is not universal. It is the appliance whose capacity, efficiency, service requirements, and installed cost fit the way the household actually lives.

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