HVAC For Beginners

Gas Tankless Water Heater Ratings

A Repairman Reviews The Brands

With our gas tankless water heater ratings, you can compare units side by side using our Head To Head tool. You can compare the models from all brands in nine categories such as warranty, efficiency, water flowrate, & where they are made. You can also read the individual reviews of each brand below. Our simple rating system gives each brand a color code and a star rating. If the card is green, then, that is one of the top picks from HvacRepairGuy. If the card is yellow, then, that would be a budget pick from HvacRepairgGuy. If the card is red, then, the brand is not recommended by HvacRepairGuy. With our gas tankless water heater reviews you can cut through the sales hype and find value. It truly is like you were taking a repairman shopping with you!

HvacRepairGuy's 2023 Top Pick

AMERICAN

★ ★ ★ ★ ☆

This brand is a part of AO Smith and offers a wide selection of units in both indoor and outdoor mounted units as well as natural and LP gas models. The water heaters use patented X3 scale prevention technology which provides for a 3X longer unit lifespan. They use copper primary heat exchangers with durable stainless steel secondary heat exchangers on condensing models. Their unique air-fuel ratio sensor monitors and optimizes combustion efficiency by varying the speed of the combustion fan. The units have digital controls and are backed by a good guarantee.

AO SMITH

★ ★ ★ ★ ☆

This brand offers a wide selection of units in both indoor and outdoor mounted units as well as natural and LP gas models. The water heaters use patented X3 scale prevention technology which provides for a 3X longer unit lifespan. They use copper primary heat exchangers with durable stainless steel secondary heat exchangers on condensing models. Their unique air-fuel ratio sensor monitors and optimizes combustion efficiency by varying the speed of the combustion fan. The units have digital controls and are backed by a good guarantee but they must be installed by a professional.

BOSCH

★ ★ ★ ★ ☆

The T9900i models, a part of their Greentherm 9000 Series, offers two sizes of high efficiency water heaters with digital controls. They are Wi-Fi enabled and can be monitored and controlled through their smartphone app. They feature auto tuning where, when they are first installed, they automatically make adjustments to maximize efficiency. The Therm Series offers two sizes of standard efficiency water heaters with digital controls but they are not Wi-Fi enabled. The units are made in the USA and are backed by a very good guarantee but they are sold through factory authorized dealers.

BRADFORD WHITE

★ ★ ★ ☆ ☆

This brand is made in the USA and is backed by a good guarantee but is only sold through authorized installers. The units feature SRT scale reduction technology which includes internal turbulators, a vertical modulating burner, & dual fan combustion control. The RTG-199ME models are standard efficiency units with a 7.3 GPM flowrate and a .82 efficiency rating while the RTG-199HE model is a high efficiency condensing water heater with a 8.3 GPM flowrate and a .92 efficiency. The Infiniti K Series models are high efficiency condensing units that have self calibrating sensors so that, upon installation, they automatically make adjustments to maximize efficiency.

ECCOTEMP

★ ☆ ☆ ☆ ☆

This brand can be purchased directly from the manufacturer through their website or Amazon store. They offer standard efficiency units for indoor installation and they are backed by a decent guarantee. The FVi12 Series offers water heaters with mechanical controls and a 4 GPM flowrate while the i12 models have electronic controls. The units require semi-annual descaling to maintain rated operation.

GLOW

★ ★ ★ ★ ☆

This brand is made and sold in Canada through a limited dealer network and the units are backed by a very good guarantee. The water heaters feature durable stainless steel heat exchangers and on board storage of 1 gallon of water in the heat exchanger. They have modulating digital controls with a durable ECM fan motor and the units are vented with PVC pipe which is cheaper and easier than stainless steel venting.

GSW

★ ★ ★ ★ ★

This brand is a part of A.O. SMITH and is made and sold in Canada through many hardware and home improvement stores. The GSWT-540H water heaters are high efficiency units with a copper primary heat exchanger and a durable stainless steel secondary heat exchanger. The units have an air-fuel ratio sensor that monitors and optimizes combustion efficiency by varying the speed of the combustion fan. The unit has a 10 gallons per minute capacity and is backed by a very good guarantee.

JOHN WOOD

★ ★ ★ ★ ☆

These water heaters are made in Canada by GSW which is owned by A.O. SMITH. The units are only installed by their authorized dealers but they are backed by a very good guarantee. They have a copper primary heat exchanger and a durable stainless steel secondary heat exchanger. The units have an air-fuel ratio sensor that monitors and optimizes combustion efficiency by varying the speed of the combustion fan. They are available in three sizes with capacities of 6.6, 8, or 10 GPM.

LAARS

★ ★ ★ ★ ☆

These water heaters are made in the USA and the brand is a part of Bradford White. The units are only installed by their authorized dealers but they are backed by a very good guarantee. The LT Series offers high efficiency units with durable stainless steel heat exchangers which resist corrosion. They have an oval pipe design which creates less scale build-up, increased thermal efficiency and lower maintenance. the units have a 0.95 efficiency rating with a 5.1 gallon per minute flow rate.

MAREY

★ ☆ ☆ ☆ ☆

These water heaters are made in China and are sold throughout North America. They can be purchased through the manufacturer's website as well as their Amazon store but their guarantee is not as good as other brands. The GA24CSA model is a standard non-condensing water heater with digital controls and an 8.34 gallon per minute water flow rate. The units use stainless steel venting which is expensive compared to units that use PVC pipe.

MIZUDO

★ ☆ ☆ ☆ ☆

These water heaters are made in China for Fogatti Inc and they can be purchased through their website as well as their Amazon store but their guarantee is not as good as other brands. The Comfortech 80 & 100 models feature durable copper heat exchangers and digital controls. They are available in natural or LP gas models and they are rather inexpensive compared to other brands.

NORITZ

★ ★ ★ ★ ★

This brand is made in China and is sold through dealers in the USA. The brand uses durable stainless steel for both the primary and secondary heat exchangers and they are backed by a very good guarantee. The EZ Series models are high efficiency water heaters that are Wi-Fi enabled and can be controlled through the Noritz Connect app. They are designed with the water connections on the top which makes it easier to connect when replacing a traditional tank water heater. The NRCR models have a built-in recirculation pump and an Auto learning mode where the unit learns your normal water usage patterns and turns on the pump to put hot water at the tap when needed.

RELIANCE

★ ★ ★ ★ ☆

This brand is a part of AO Smith and offers a wide selection of units in both indoor and outdoor mounted units as well as natural and LP gas models. The water heaters can be purchased at various hardware and home improvement stores and is backed by a very good guarantee. They use copper primary heat exchangers with durable stainless steel secondary heat exchangers on condensing models. All of the units use digital controls with the condensing models also having a remote control. The C Series non-condensing models allow concentric venting while the U Series requires separate intake and exhaust pipes.

RHEEM

★ ★ ★ ★ ☆

This brand is made in the USA and offers models that have digital controls and they can be purchased through many home improvement stores. The units can be Wi-Fi enabled with the addition of an option kit and they are backed by a very good guarantee. The Performance Plus series offers standard efficiency water heaters in three sizes for either indoor or outdoor installation. They feature concentric venting and have a remote control but their guarantee is not as good as the high efficiency models. The Performance Platinum Series offers high efficiency units with a built-in recirculation pump to have ready hot water at the tap which reduces water consumption and waste. They have built-in gas and water leak detectors and they have an 11 gallon per minute capacity with a .93 efficiency. The Ikonic Series offers super high efficiency models with a .96 efficiency and a 8.4 GPM capacity as well as built-in Wi-Fi control.

RICHMOND

★ ★ ★ ☆ ☆

These water heaters are made in Mexico by RHEEM MANUFACTURING and can be purchased at Menards home improvement stores. The Encore Series RMTG models are basic non-condensing water heaters while the RMTGH models are high efficiency units. All of the units can be monitored and controlled through Wi-Fi and the EcoNet app but it requires an optional kit to be installed. The RMTGH models include an easy to install wall hanging bracket and all of the units are backed by a very good guarantee.

RINNAI

★ ★ ☆ ☆ ☆

This brand is made in the USA, is backed by a very good warranty, and can be purchased at various retailers as well as through their Amazon store. The RE Series models are standard efficiency water heaters with concentric venting and digital controls. They are available in four sizes and for either indoor or outdoor installation and offer optional Wi-Fi and recirculation pump kits. The RSC models are high efficiency units with a built-in recirculation pump and smart technology where the system monitors water usage for a week then adjusts the recirculation pump operating schedule. This saves energy while also minimizing water wasted. The RU models are high efficiency water heaters that are available in four sizes but they do not have a recirculation pump.

RUUD

★ ★ ★ ☆ ☆

This brand is made in the USA by Rheem Manufacturing and offers models that have digital controls. The RUTG Series units are standard efficiency water heaters that can be Wi-Fi enabled with the addition of an optional kit. They are available in three sizes for either indoor or outdoor installation and feature concentric venting as well as a remote control. The SR Series offers high efficiency units with a built-in recirculation pump to have ready hot water at the tap which reduces water consumption and waste. They have built-in Wi-Fi control and are available in two sizes. The Ultra Series offers high efficiency models with a .93 efficiency and a 9.5 GPM capacity as well as built-in Wi-Fi control. The brand is available through authorized dealers but their guarantee is not as good as some of the other brands.

STATE

★ ★ ★ ☆ ☆

This brand is a part of AO Smith and offers a wide selection of units in both indoor and outdoor mounted units as well as natural and LP gas models. The water heaters use patented X3 scale prevention technology which provides for a 3X longer unit lifespan. They use copper primary heat exchangers with durable stainless steel secondary heat exchangers on condensing models. Their unique air-fuel ratio sensor monitors and optimizes combustion efficiency by varying the speed of the combustion fan. The units have digital controls and are backed by a good guarantee but are sold through authorized installers.

TAKAGI

★ ★ ★ ★ ☆

This brand is a part of AO Smith and offers a wide selection of units in both indoor and outdoor mounted units as well as natural and LP gas models. The water heaters use patented X3 scale prevention technology which provides for a 3X longer unit lifespan. They use copper primary heat exchangers with durable stainless steel secondary heat exchangers on condensing models. Their unique air-fuel ratio sensor monitors and optimizes combustion efficiency by varying the speed of the combustion fan. The units have digital controls and are backed by a good guarantee but are sold through authorized installers.

WAIWELA

★ ★ ★ ☆ ☆

This brand is made in Japan by PALOMA and they offer both indoor and outdoor units. The PH2 models are standard efficiency water heaters with concentric venting and they are available in three sizes. The PHH models are high efficiency units that feature durable stainless steel secondary heat exchangers but use copper for the primary heat exchanger. They have digital controls with a remote and are available in two sizes. It is not easy to find a dealer for this brand and their guarantee is only average when compared to other brands.

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