Natural Gas Indoor Residential Tankless Water Heaters
Choose from our two residential tankless water heaters: Onsen 14L and Onsen 26L.
Need help choosing your Onsen? View the comparison chart.
Looking for a Propane Gas unit instead. Click here.
Which size is right for you?
When choosing your Onsen indoor water heater, the most important factor to consider is the number of fixtures or bathrooms that the unit will supply.
![](https://cdn.shopify.com/s/files/1/0642/4130/3774/files/14L_Comparison.jpg?v=1716394751)
Onsen 14L
- Compact & Energy Efficient
- Indoor
- Propane or Natural Gas
- 120V
- 1-2 Applications (1 bathroom)
- 97,000/100,000 BTU/h
- 32 lbs
- 25.94 x 13.9 x 5.59 in.
- Direct Vent (3" dia.)
- ½" Gas/Water Fittings
For a 1-bath apartment, tiny home, cabin, or cottage, choose the Onsen 14L.
![](https://cdn.shopify.com/s/files/1/0642/4130/3774/files/26L_Comparison.jpg?v=1716394751)
Onsen 26L
- Powerful & Energy Efficient
- Indoor
- Propane or Natural Gas
- 120V
- 2-3 Applications (2 bathrooms)
- 180,000 BTU/h
- 44 lbs
- 27.24 x 17.13 x 8.08 in.
- Direct Vent (3" dia.)
- ¾" Gas/Water Fittings
For a 2-bath family home, townhouse or cottage, choose the Onsen 26L.