An electric tankless heater needs no gas line or vent and is nearly 100% efficient at the heater. The catch is power: a whole-home unit draws 100 to 150 A on several 240 V breakers, so check your panel first. Small 3 to 13 kW units fit under a sink or serve one shower in a warm climate; 27 kW and up handles a whole home where incoming water isn’t too cold.
Prices were last checked October 31, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.
Full ranking 20
- EcoSmart ECO 36#1 of 20Full review
For a large home with 300 A service that wants all electric hot water. The lifetime warranty and low price per kilowatt make it a strong value if a pro installs it.
Amazon $699$69936 kW8.8 GPM0.94 - Stiebel Eltron Tempra 36 Trend#2 of 20Full review
The pick for a larger home with 300 A service that wants electric whole house hot water, even in cooler regions. Few electric heaters match its power and warranty.
Amazon $749$74936 kW7.5 GPM0.98 - Stiebel Eltron Tempra 29 Trend#3 of 20Full review
For homes with 200 A service in mild climates that want two showers at once from one heater.
Amazon $639.99$639.9928.8 kW6 GPM0.98 - Stiebel Eltron Tempra 24 Trend#4 of 20Full review
A whole home heater for a two bathroom house in a warm or mild climate with 150 A service or more. The 7 year leakage warranty is the main reason to pay over the Rheem.
Amazon $514.23$514.2324 kW5 GPM0.97 - EcoSmart ECO 11#5 of 20Full review
For a single shower or a pair of sinks in a warm climate, with a lifetime warranty if a pro installs it.
Amazon $244.78$244.7813 kW3.2 GPM0.92 - Westinghouse WET-24K-G#6 of 20Full review
For buyers who want app control on a whole home electric heater. Without published warranty terms, the Stiebel Tempra 24 Trend is the safer buy at the same price.
Amazon $499.99$499.9924 kW5.5 GPM- - EcoSmart ECOS 27#7 of 20Full review
A low cost whole home heater for a two bathroom house in a warm climate. The short warranty is the tradeoff for the price.
Amazon $549$54927 kW6.6 GPM0.94 - EcoSmart ECO 8#8 of 20Full review
For a faucet far from the main water heater. A lifetime warranty at a low price makes it a safe point of use pick if you hire the install out.
Amazon $219$2198 kW2 GPM0.96 - Stiebel Eltron Tempra 20 Trend#9 of 20Full review
For a small home or apartment in a warm climate with 125 A service. The Tempra 24 costs little more and gives more headroom.
Amazon $544.43$544.4319.2 kW4 GPM0.97 - Bosch Tronic 6100 C 27#10 of 20Full review
For a two bathroom home in a warm climate that wants a compact whole home heater with a 2 year parts warranty, double what Rheem gives.
Amazon $636.60$636.6027 kW5.3 GPM0.93 - Stiebel Eltron DHX 12-2 Trend#11 of 20Full review
For adding fast hot water to a far sink or a single shower in a warm climate. The long warranty sets it apart from cheaper point of use units.
Amazon $266.14$266.1412 kW2.5 GPM0.96 - Rheem RTEX-24#12 of 20Full review
A mainstream whole home heater for a two bathroom house in a warm climate. The Stiebel Tempra 24 Trend costs about the same with a longer warranty.
Amazon $549$54924 kW5.9 GPM0.93 - Camplux TEW18#13 of 20Full review
A budget whole home heater for a small home in a warm climate. Buyers who want published flow and efficiency figures should pay more for a Stiebel or EcoSmart.
Amazon $278.95$278.9518 kW-- - EcoSmart ECOS 18#14 of 20Full review
For a small home or apartment in a warm climate that wants whole house hot water on two breakers. Amazon stock was low when checked.
Amazon $449$44918 kW4.4 GPM0.96 - Bosch Tronic 4000 C 10#15 of 20Full review
For a busy kitchen sink or a pair of sinks that need more flow than a small point of use heater gives.
Amazon $251.99$251.9910.5 kW2 GPM0.95 - Bosch Tronic 6100 C 18#16 of 20Full review
For a small home or apartment in a warm climate that wants the Bosch name. Most buyers get more power for the money elsewhere.
Amazon $585.46$585.4618 kW3.5 GPM0.94 - Stiebel Eltron Tempra 15 Plus#17 of 20Full review
For a small home or cabin on a 100 A service in a warm climate where a steady shower temperature matters more than flow. Homes with more service get more for the money from a Trend model.
Amazon $619$61914.4 kW3 GPM0.96 - Bosch Tronic 4000 C 8#18 of 20Full review
For instant hot water at a kitchen or bathroom sink far from the main heater.
Amazon $229$2298.5 kW1.6 GPM0.92 - Rheem RTEX-11#19 of 20Full review
For a single shower or a pair of sinks in a warm climate. The EcoSmart ECO 11 costs less and carries a lifetime warranty.
Amazon $268.99$268.9911 kW2.7 GPM0.92 - Rheem RTEX-06T#20 of 20Full review
For instant hot water at a single bathroom or kitchen sink on a budget.
Amazon $189$1896.5 kW1.6 GPM0.94