What it delivers
The Ranein RHO19K-NG 190,000 BTU Natural Gas Outdoor Tankless Water Heater is an outdoor gas tankless with a 190,000 BTU/h burner and a stated maximum flow of 8.5 GPM.
Expect about 4.2 GPM with cold winter water (a 70°F rise) and 6.5 GPM when the inlet is milder (45°F rise); that is 2 showers at 2 GPM in January. Run your house through the planner.
At full fire it burns about 183 cubic feet of natural gas an hour. The gas line has to carry that on top of the furnace, range and dryer; a gas fitter sizes the pipe from its length and the total load.
Outdoor units vent straight out of the cabinet, which saves the vent run and the wall penetration; plan for freeze protection and a pipe cover where winters bite.
Listed details: features: LED Display; connections: 3/4" npt; material: Natural Gas; model: RHO19K-NG.
The listing gives dimensions of 15.08 in (W) x 24.25 in (H) and a weight of 44 lb.
Right unit for this house?
Install it when
- Houses running 2 showers at once in winter
- Replacing a gas tank heater
Look at another unit when
- More than 2 winter showers at once
- Homes without a gas line
Strengths and trade-offs
Strengths
- 190,000 BTU/h input
- Up to 8.5 GPM
- No vent pipe
Trade-offs
- Gas line may need upsizing
- Needs freeze protection outdoors
- Needs periodic descaling
Install limits
- Figures are the maker's or seller's own. Flow at a rise is our estimate from the input; gas, venting and electrical work needs a licensed professional.
Rated performance
Every figure below comes from the source shown in brackets. Where the maker doesn't state something, we say so instead of estimating.
| Model number | RHO19K-NG | Retailer |
|---|---|---|
| Dimensions (seller) | 15.08"W x 24.25"H | Retailer |
| Features (seller) | LED Display | Retailer |
| Voltage | 120 V AC | Retailer |
| Max flow (maker) | 8.5 GPM | Retailer |
| Input (maker) | 190,000 BTU/h | Retailer |
| Product weight | 44 lb | Retailer |
| Material | Natural Gas | Retailer |
| Fuel | Natural Gas | Retailer |
| Connections | 3/4" npt | Retailer |
Rival units at this flow
More gas tankless water heaters rated for similar demand
- MIZUDO HS180A0W-NG 180,000 BTU Natural Gas Outdoor Tankless Water Heater
- Westinghouse HS180A0G-LP 180,000 BTU Propane Outdoor Tankless Water Heater
- Rheem RTG-70XLP-3 160,000 BTU Propane Outdoor Tankless Water Heater
- Rheem RTG-70XLN-3 160,000 BTU Natural Gas Outdoor Tankless Water Heater
Full gas tankless water heaters spec grid · Every Ranein unit in the catalog
Final verdict
A well-specified outdoor gas tankless for houses running 2 showers at once in winter.
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