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156 complete heaters, 70 service parts and kits

Tankless water heater reviews: every model rated (2026)

Looking for tankless water heater reviews you can compare? Here is every heater and part we review, 226 in total, best-rated first: the Rheem 18 kW Electric, 240V leads at 9.3/10. Each rating comes from buyer reviews or, where there are none yet, from what the listing documents.

Category
Rating

24 products

9.3/10
Rheem 18 kW Electric, 240V
4.4 GPM · 18 kW · 240 VRheem 18 kW Electric, 240V$422.92 on Sep 30, 2026, may have changed2,187 buyer reviews
9.2/10
MIZUDO 199,000 BTU Natural Gas Indoor
10.3 GPM · 199,000 BTU/h · 120 VMIZUDO 199,000 BTU Natural Gas Indoor$1,199 on Sep 30, 2026, may have changed307 buyer reviews
9.1/10
FOGATTI Outdoor Propane Tankless
120,000 BTU/h · 120 VFOGATTI Outdoor Propane Tankless$529.99 on Sep 30, 2026, may have changed166 buyer reviews
8.3/10
Rheem RTEX-24, 24 kW 240V
5.9 GPM · 24 kW · 240 VRheem RTEX-24, 24 kW 240V$549 on Sep 30, 2026, may have changed893 buyer reviews
8.1/10
WINTEMP WN-36kW Electric, 240V
8.7 GPM · 36 kW · 240 VWINTEMP WN-36kW Electric, 240V$499.98 on Sep 30, 2026, may have changed203 buyer reviews
8.0/10
A. O. Smith 10 GPM Natural Gas Outdoor
10 GPM · 199,000 BTU/hA. O. Smith 10 GPM Natural Gas Outdoor$1,599.99 on Sep 30, 2026, may have changedSpec-based rating
7.9/10
ThermoMate 14 kW Electric, 240V
3.4 GPM · 14 kW · 240 VThermoMate 14 kW Electric, 240V$249.99 on Sep 30, 2026, may have changedSpec-based rating
7.9/10
Ranein 190,000 BTU Natural Gas Indoor
8.5 GPM · 190,000 BTU/hRanein 190,000 BTU Natural Gas Indoor$699 on Sep 30, 2026, may have changed710 buyer reviews
7.9/10
Stiebel Eltron Tempra 29 Plus
28.8 kW · 240 VStiebel Eltron Tempra 29 Plus$798.99 on Sep 30, 2026, may have changed451 buyer reviews
7.8/10
Rheem RTGH 9.5 GPM Propane Indoor
9.5 GPM · 199,900 BTU/hRheem RTGH 9.5 GPM Propane Indoor$1,383.15 on Sep 30, 2026, may have changedSpec-based rating
7.8/10
Rinnai RU199iN Condensing
11 GPMRinnai RU199iN CondensingSee current price388 buyer reviews
7.8/10
ThermoMate CZ422LP Propane Indoor
5 GPM · 113,000 BTU/h · 120 VThermoMate CZ422LP Propane Indoor$399.99 on Sep 30, 2026, may have changedSpec-based rating
7.7/10
ORBEK 14 kW Electric, 240V
3.38 GPM · 14 kW · 240 VORBEK 14 kW Electric, 240V$189.99 on Sep 30, 2026, may have changedSpec-based rating
7.7/10
SIVUATEK 18 kW Electric, 240V
4.3 GPM · 18 kW · 240 VSIVUATEK 18 kW Electric, 240V$245.99 on Sep 30, 2026, may have changed266 buyer reviews
7.7/10
Rheem RTG 8.4 GPM Natural Gas Outdoor
8.4 GPM · 180,000 BTU/hRheem RTG 8.4 GPM Natural Gas Outdoor$964.10 on Sep 30, 2026, may have changedSpec-based rating
7.7/10
ThermoMate Condensing Natural Gas
5.28 GPM · 114,000 BTU/h · 120 VThermoMate Condensing Natural Gas$559.99 on Sep 30, 2026, may have changedSpec-based rating
7.7/10
Westinghouse 14 kW Electric, 240V
14 kW · 240 VWestinghouse 14 kW Electric, 240V$319.99 on Sep 30, 2026, may have changedSpec-based rating
7.6/10
Marey 170,000 BTU Propane Indoor
7.5 GPM · 170,000 BTU/hMarey 170,000 BTU Propane Indoor$772.46 on Sep 30, 2026, may have changedSpec-based rating
7.6/10
MIZUDO 120,000 BTU Natural Gas
5.1 GPM · 120,000 BTU/hMIZUDO 120,000 BTU Natural Gas$539.99 on Sep 30, 2026, may have changedSpec-based rating
7.6/10
MIZUDO 120,000 BTU Propane
5.1 GPM · 120,000 BTU/hMIZUDO 120,000 BTU Propane$539.99 on Sep 30, 2026, may have changedSpec-based rating
7.6/10
PROCURU 18" Flexible Gas Connector Kit
PROCURU 18" Flexible Gas Connector Kit$28.89 on Sep 30, 2026, may have changedSpec-based rating
7.6/10
Rheem RTG 7.0 GPM Natural Gas Outdoor
7 GPM · 160,000 BTU/hRheem RTG 7.0 GPM Natural Gas Outdoor$819.08 on Sep 30, 2026, may have changedSpec-based rating
7.6/10
Rheem RTG 8.4 GPM Propane Indoor
8.4 GPM · 180,000 BTU/hRheem RTG 8.4 GPM Propane Indoor$953 on Sep 30, 2026, may have changedSpec-based rating
7.6/10
ThermoMate Condensing Propane
5.28 GPM · 114,000 BTU/h · 120 VThermoMate Condensing Propane$559.99 on Sep 30, 2026, may have changedSpec-based rating

Product images: Amazon listings

Related rankings

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MIZUDO 199,000 BTU Natural Gas Indoor#1: MIZUDO 199,000 BTU Natural Gas Indoor · 9.2/10Best Tankless Water Heaters in 20265 models rankedFOGATTI Outdoor Propane Tankless#1: FOGATTI Outdoor Propane Tankless · 9.1/10Best Outdoor Propane Tankless Water Heaters in 20265 models rankedRheem 18 kW Electric, 240V#1: Rheem 18 kW Electric, 240V · 9.3/10Best Whole-House Electric Tankless Water Heaters in 20265 models rankedRinnai RU199iN Condensing#1: Rinnai RU199iN Condensing · 9.1/10Best High-Efficiency Condensing Tankless Water Heaters in 20265 models rankedMIZUDO 199,000 BTU Natural Gas Indoor#1: MIZUDO 199,000 BTU Natural Gas Indoor · 9.2/10Best Gas Tankless Water Heaters in 20265 models rankedMIZUDO 199,000 BTU Natural Gas Indoor#1: MIZUDO 199,000 BTU Natural Gas Indoor · 9.2/10Best Whole-House Tankless Water Heaters in 2026: Gas and Electric5 models ranked

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