What it delivers
The Orbek HS120 120,000 BTU Natural Gas Outdoor Tankless Water Heater is an outdoor gas tankless with a 120,000 BTU/h burner and a stated maximum flow of 5.1 GPM.
Flow depends on how cold the incoming water is. Our estimate from its input: 4.1 GPM at a 45°F rise, falling to 2.6 GPM at 70°F, which is 1 shower at 2 GPM on a cold-climate winter day. Size it to your fixtures and climate.
At full fire it burns about 116 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.
Also on the listing: material: Natural Gas; model: HS120.
The listing gives dimensions of 15.51 in (W) x 23.94 in (H) and a weight of 29.3 lb.
Warranty, per the listing: The entire unit is covered by a 2-year warranty, The heat exchanger is covered by a 5-year warranty.
Right unit for this house?
Install it when
- One shower at a time in cold climates
- Replacing a gas tank heater
Look at another unit when
- More than 1 winter shower at once
- Homes without a gas line
Strengths and trade-offs
Strengths
- 120,000 BTU/h input
- Up to 5.1 GPM
- No vent pipe
Trade-offs
- Gas line may need upsizing
- Needs freeze protection outdoors
- Scale builds up without flushing
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 | HS120 | Retailer |
|---|---|---|
| Dimensions (seller) | 15.51"W x 23.94"H | Retailer |
| Voltage | 120 V AC | Retailer |
| Max flow (maker) | 5.1 GPM | Retailer |
| Input (maker) | 120,000 BTU/h | Retailer |
| Product weight | 29.3 lb | Retailer |
| Warranty | The entire unit is covered by a 2-year warranty, The heat exchanger is covered by a 5-year warranty | Retailer |
| Material | Natural Gas | Retailer |
| Fuel | Natural Gas | Retailer |
Rival units at this flow
More gas tankless water heaters rated for similar demand
- VancEpic V-RHO13K-NG 130,000 BTU Natural Gas Outdoor Tankless Water Heater
- Ranein RHO13K-LPG 130,000 BTU Propane Outdoor Tankless Water Heater
- Ranein RHO13K-NG 130,000 BTU Natural Gas Outdoor Tankless Water Heater
- Camplux WA528 150,000 BTU Natural Gas Outdoor Tankless Water Heater
Full gas tankless water heaters spec grid · Every Orbek unit in the catalog
Final verdict
A practical outdoor gas tankless for one shower at a time in cold climates.
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