Best Water Heaters 2026: Tankless, Gas, and Heat Pump Picks

Tankless is a simple promise: hot water that never runs out, from a box the size of a carry-on. The 27 kW EcoSmart is the unit that made that promise mainstream on the electric side, and the ECOS 27 is the listing carrying it today. Its self-modulating design draws only the power the current flow demands, and at $549.00 verified it is still the cheapest way to buy 27 kW of electric heating.

The honest physics: electric tankless output depends on how cold your incoming water is. In Texas and the Sun Belt, where groundwater arrives warm, a 27 kW unit comfortably runs a shower and a sink together. In Minnesota it becomes a one-fixture unit in January. Read our GPM explainer below, then our amperage explainer, before committing. One more thing to weigh at today's prices: the Stiebel Tempra 24 now lists slightly below this unit, so the choice is 3 kW of headroom against German build for roughly the same money. If the panel math kills electric outright, the gas Rinnai RE140eN route below sidesteps the electrical question entirely.

If the ECOS 27 is the power answer, the Tempra is the engineering answer. Stiebel Eltron is to electric water heating what Miele is to laundry: a German specialist that has been refining one product family for generations. The Tempra 24 Trend brings that pedigree at $533.22 verified.

The buying logic against the ECOS 27 used to be pure philosophy, with a $226 premium attached. That premium is gone: the Tempra currently lists about $16 under our top pick. Same fundamental technology, same electrical demands, same endless hot water, 3 kW less rated power. If you live where groundwater arrives warm and you value build over headroom, this is now the rational buy rather than the sentimental one. Bigger households in colder regions should look at the Tempra 36 PLUS below instead.

The smartest tankless installs are often the small ones. Instead of one giant unit fighting the whole house's demand, a right-sized unit like this 8 kW Rheem serves one zone cleanly, and its much smaller electrical footprint means the panel conversation gets easy rather than expensive.

Rheem's brand is the other half of the story: this is the name on millions of American water heaters, with the parts availability and plumber familiarity that follow. At $239.00 verified it is the easy answer for the garage apartment, the cabin, or the workshop sink. Size it honestly, though; if you want a full shower on one unit, the 13 kW EcoSmart ECO 11 is the better small-electric buy, and whole-house shoppers should step up to the RTEX-27 or our top pick.

The ECOS 18 exists for one buyer: the household whose electrical panel, not budget, is the constraint. Dropping from 27 kW to 18 kW takes the listed draw from 112.5 amps to 75, which can be the difference between a straightforward electrician visit and a panel upgrade quote.

The money argues the other way. At $411.73 verified you save $137 against the ECOS 27 and give up a third of the heating power, which in a cold-inlet winter is exactly the third you will miss. If your panel can host the 27, buy the 27 and enjoy the headroom; the 18 is strictly the panel-constrained play, and a fair one, since a right-sized unit that installs cleanly beats a bigger one that triggers a service upgrade.

Rheem's pitch is not the spec sheet; it is the year-six service call. When a heating element or sensor eventually needs attention, the brand with parts in every supply house and a name every plumber knows becomes the easy unit to keep running. That is what $649.99 verified buys over the identically rated ECOS 27.

Against the Stiebel Tempra 24, the RTEX-27 costs $117 more and answers with 3 kW more power and American ubiquity instead of German refinement. There is no wrong answer among the three whole-house electrics here; there is only which insurance you prefer, lowest price, deepest pedigree, or biggest service network. Rheem is the third option, and for many households the most practical one.

Cold groundwater is the enemy of electric tankless, and the Tempra 36 PLUS is the biggest hammer available against it. Where a 27 kW unit in a northern winter becomes a single-shower machine, 36 kW keeps multi-fixture life plausible. At $1,023.44 verified it costs nearly double the Tempra 24, so buy it for the temperature rise, not the badge.

The panel is the harder cost. This is the point in the guide where our amperage explainer below stops being advice and becomes the whole purchase decision: a unit this size can demand more capacity than an older service has to give. Electrician first, checkout second. And run the gas comparison honestly at this price, because the Rinnai RX160iN is only $79 further up and delivers big-household hot water with zero panel drama.

The ECO 11 and the 8 kW Rheem above are the two ways to buy the same smart idea: put the heat where the water gets used. At $244.49 verified, the ECO 11 is the stronger pick of the pair, buying 5 kW more temperature rise for $5.49 more money.

In a warm-groundwater climate this class of unit runs a full bathroom with ease, which is why the point-of-zone strategy is quietly the best hot water upgrade in sprawling single-story homes: no more marathon waits while cold pipe empties toward the far bathroom. Pick the EcoSmart for power, the Rheem for the service network, and either way size honestly: one zone per unit.

When the whole family showers back to back on a January morning, gas is still king. Electric tankless output rises and falls with groundwater temperature; a gas burner does not care. Rinnai has spent decades as the reference brand in this category, and the RX160iN is a current condensing model, extracting extra efficiency from exhaust heat that older non-condensing designs simply vent away.

The decision against our electric top pick comes down to climate, household size, and infrastructure: if you have a gas line, a cold winter, or three teenagers, the Rinnai premium buys certainty no electric unit at any price can offer, and our head-to-head below runs the full argument. Note how close this now sits to the Tempra 36 PLUS, which is the moment the gas conversation gets serious for cold-climate buyers. If the price still stings, the RE140eN below is the value door into the same brand.

The cheapest thing about outdoor gas tankless is the installation you skip. Indoor gas units need sealed venting run through walls or roof, a significant chunk of any install quote. The RE140eN mounts on an exterior wall and vents to the air around it, which in mild-winter country turns a major project into a modest one.

At $795.69 verified you get Rinnai's burner pedigree in the value tier, and the listing's 5.3 GPM covers a real household's rhythm in warm-groundwater country, where the outdoor mount thrives. The trade against the flagship is condensing efficiency: this unit sends its exhaust heat out the vent instead of harvesting it. Northern buyers should spend up for the indoor RX160iN; this one belongs on a Texas wall.

Every other electric unit here makes heat; this one moves it, and that is why it wins the utility-bill decade. A heat pump water heater pulls warmth from the surrounding air into the tank, delivering hot water for a fraction of the running cost of resistance heating. Senville's listing puts the saving at up to 70 percent against a standard electric heater, and over a ten-year life that difference commonly adds up to more than the unit's price.

The Energy Star badge is also a key that opens incentive doors: federal efficiency tax credits and utility rebates frequently apply to this class, so your net price may land well below the $1,099.99 verified sticker, which already sits level with our gas flagship, the RX160iN, rather than above it. The trades are honest ones, finite tank capacity and the need for a reasonably warm host space with room for a 66.5 inch tank. For a garage in Texas, it is close to a perfect appliance.

The most common hot water complaint in America is not capacity; it is the fifty-foot wait. Water cools in pipes between uses, so the distant sink runs cold for a minute while you pour the heater's work down the drain. A point-of-use mini tank like this GE parks a stored 2.5 gallons at the fixture, so the tap is hot the instant it opens.

At $239.00 verified, this is among the highest satisfaction-per-dollar purchases on this page. It also pairs beautifully with any whole-house unit above: let the big system do volume while the mini tank kills the wait at the one stubborn sink. Renovating the kitchen anyway? Our shower head guide covers the other end of the hot water experience.

The POU 3.5 is the minimalist's answer to the same problem the GE mini tank solves: hot water where the pipes will not bring it fast. Being tankless, it never runs out and never stores a drop, which suits low-traffic sinks, cabins, and mobile setups where a tank's bulk or standby heat makes no sense.

The choice against the GE mini tank is usage pattern. Busy family kitchen sink: the stored 2.5 gallons deliver a stronger burst. Occasional-use utility sink, shop basin, or RV: the EcoSmart's endless trickle and $56 savings win. Either way you are spending under $240 to end a daily annoyance, which is the best trade in home plumbing.