Tankless Water Heaters
Best Whole House Propane Tankless Water Heater (2026): 5 Picks Compared
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For a whole house on propane, the MIZUDO leads this list with 10.3 GPM at 199,000 BTU for 5 to 7 outlets, plus WiFi and app control. If weight matters, the APUS is the Lightest Pick at 26.9 lb, with up to 6.8 GPM at 140,000 BTU.
Starting out? See the main guide: Best Tankless Water Heater
Top picks at a glance
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Best OverallMIZUDO Propane Gas Tankless Water Heater9.8 View on Amazon -
Lightest PickAPUS Propane Tankless Water Heater9.6 View on Amazon -
Also GreatRanein Propane Gas Tankless Water Heater9.6 View on Amazon -
9.2 View on Amazon -
Also GreatRheem RTG Series 7.0 GPM Liquid Propane9.2 View on Amazon
Compare the specs
Ranked on flow rate, temperature control, phone app control from each listing, plus how many buyers have rated it. A dash (—) means we could not confirm that figure from the listing.
| Pick | Flow rate | Fuel | Temperature control | Phone app control | Weight | Warranty |
|---|---|---|---|---|---|---|
| 1. MIZUDO Propane Gas Tankless Water Heater | 10.3 GPM | Propane | Yes | Yes | 55.5 lb | 2-year |
| 2. APUS Propane Tankless Water Heater | 6.8 GPM | Propane | Yes | — | 26.9 lb | 2-year |
| 3. Ranein Propane Gas Tankless Water Heater | 8.5 GPM | Propane | — | — | 42 lb | 2-year |
| 4. Westinghouse Tankless Water Heater Propane Outdoor | 8.1 GPM | Propane | Yes | — | 42 lb | 2-year |
| 5. Rheem RTG Series 7.0 GPM Liquid Propane | 7 GPM | Liquid Propane | Yes | — | 46.5 lb | 1-year |
MIZUDO Propane Gas Tankless Water Heater
It delivers 10.3 GPM at 199,000 BTU for 5 to 7 outlets, with WiFi and app control and a 95 to 149 degree range.
- Flow rate: 10.3 GPM, the highest here
- Fuel: Propane
- Temperature control
- Phone app control
- 2-year warranty stated
Good for
- Households running 5 to 7 outlets at once
- Buyers who want app control from a phone
Skip it if
- You need more than 10.3 GPM at once
- You want a unit under 26.9 lb
It holds temperature within plus or minus 1 degree and activates at 0.53 GPM. It uses a sealed concentric direct-vent system with a 3 inch by 5 inch vent kit and a bottom-mounted forced-draft fan. It measures 24.8 inches by 15.9 inches by 10.4 inches and weighs 55.5 lb. It carries a 2-year full unit warranty and 5-year heat exchanger coverage.
APUS Propane Tankless Water Heater
It weighs 26.9 lb and delivers up to 6.8 GPM at 140,000 BTU, with a booster pump and anti-freeze protection.
- Flow rate: 6.8 GPM
- Fuel: Propane
- Temperature control
- 2-year warranty stated
- 26.9 lb, the lightest here
Good for
- Buyers who want a 26.9 lb unit
- Households using 4 to 5 water points
Skip it if
- You need more than 6.8 GPM
- You want a warranty longer than 2 years
It has a built-in booster pump that increases water flow by up to 130 percent, to a maximum of 6.8 GPM. It sets 95 to 140 degrees on an LED display or the Tuya app and holds temperature within plus or minus 1 degree. It measures 21.26 inches by 13.58 inches by 7.09 inches and uses standard 1/2 inch NPT connections. It has a UEF of 0.81 and a 2-year manufacturer warranty.
Ranein Propane Gas Tankless Water Heater
It delivers up to 8.5 GPM at 190,000 BTU for 4 to 6 outlet points, with an LED display and wall mounting.
- Flow rate: 8.5 GPM
- Fuel: Propane
- 2-year warranty stated
Good for
- Households using 4 to 6 outlet points
- Buyers who want an 8.5 GPM unit
Skip it if
- You need more than 8.5 GPM
- You want a warranty longer than 2 years
It measures 24.25 inches by 15.08 inches by 8.07 inches and weighs 42 lb. It uses standard 3/4 inch G water inlet fittings and air inlets. A blower under the unit adjusts speed with wind pressure and water temperature. It carries a 2-year warranty.
Westinghouse Tankless Water Heater Propane Outdoor
It delivers up to 8.1 GPM at 180,000 BTU for 3 to 5 fixtures, with a wired digital controller and outdoor installation.
- Flow rate: 8.1 GPM
- Fuel: Propane
- Temperature control
- 2-year warranty stated
Good for
- Households running 3 to 5 fixtures at once
- Buyers who want a wired digital controller
Skip it if
- You need more than 8.1 GPM
- You want a unit for indoor installation
It adjusts from 95 degrees to 158 degrees and holds temperature within plus or minus 1 degree. It has a variable-speed combustion fan and freeze protection for outdoor operation. It uses standard 3/4 inch NPT plumbing. It carries a 2-year limited unit warranty and a 5-year heat exchanger warranty.
Rheem RTG Series 7.0 GPM Liquid Propane
It delivers 7.0 GPM at a 35 degree temperature rise and 160,000 BTU per hour for 2 to 3 simultaneous showers.
- Flow rate: 7 GPM
- Fuel: Liquid Propane
- Temperature control
- 1-year warranty stated
Good for
- Households running 2 to 3 showers at once
- Buyers who want a digital LED temperature panel
Skip it if
- You need more than 7.0 GPM
- You need more than 2 to 3 simultaneous showers
It has a digital LED temperature control panel with plus or minus 1 degree adjustments and built-in freeze protection. It has a 0.82 Uniform Energy Factor and a non-condensing design. It uses a direct vent system for indoor installation and includes mounting hardware. It carries a 15-year heat exchanger warranty and a 5-year parts warranty.
How to choose
Flow rate and outlet count
Flow rate, in gallons per minute, is how much hot water a unit can deliver at once. A higher flow rate supports more outlets running together. The MIZUDO delivers 10.3 GPM for 5 to 7 outlets, the Ranein delivers 8.5 GPM for 4 to 6 outlet points, the Westinghouse delivers 8.1 GPM for 3 to 5 fixtures, the Rheem delivers 7.0 GPM for 2 to 3 simultaneous showers, and the APUS delivers up to 6.8 GPM for 4 to 5 water points. Compare the flow rate and the outlet count with how many showers, faucets and appliances run together in your home.
Temperature control and range
Temperature control sets the outlet temperature and holds it during use. The MIZUDO adjusts from 95 degrees to 149 degrees, the APUS sets 95 degrees to 140 degrees, and the Westinghouse adjusts from 95 degrees to 158 degrees. The MIZUDO, APUS, Westinghouse and Rheem hold temperature within plus or minus 1 degree. The Rheem uses a digital LED temperature control panel. Check the range against the hottest use you need.
Indoor, outdoor and venting
Indoor units vent through a direct-vent system, while outdoor units are built for outside installation. The MIZUDO uses a sealed concentric direct-vent system with a 3 inch by 5 inch vent kit for indoor installation. The Rheem uses a direct vent system for indoor installation. The Westinghouse is built for outdoor installation with freeze protection. All five units have freeze protection or anti-freeze protection.
FAQ
What flow rate do I need for a whole house?
Compare the flow rate with how many outlets run together. The MIZUDO delivers 10.3 GPM for 5 to 7 outlets, while the APUS delivers up to 6.8 GPM for 4 to 5 water points.
Do these water heaters work with propane?
Yes. The MIZUDO, APUS, Ranein and Westinghouse use propane, and the Rheem uses liquid propane.
Which unit is the lightest pick here?
The APUS is the Lightest Pick at 26.9 lb, followed by the Ranein and Westinghouse at 42 lb each.
