Whether or not you need to increase your gas line size will depend on a few factors. In most cases this should be discussed with an installer during the estimation phase. All of our residential units are compatible with a 1/2″ gas line if the correct conditions are met.
In addition to gas line size, the length of the line, the number of other gas appliances sharing the gas supply, the gas meter and gas regulator (if applicable) all need to be evaluated. Most tank style gas water heaters are well under 100,000 BTU1 while most tankless units are over 160,000 BTU. The gas system in your home was likely sized and built around a lower total BTU demand than it would be with a tankless water heater.
If you are replacing a tankless with another tankless that did not experience any problems that could be attributed to an undersized gas line, it’s a good indication that the existing gas line will be sufficient. Though, it should still be evaluated by the installer if a higher BTU tankless is being put in.
The installation manual, which can be downloaded from our Support Site, will have various gas sizing charts and other diagrams related to sizing the gas line.
For help with specific sizing, consult with a licensed plumber to determine exact size needed.
Please visit http://www.noritz.com to find a local installer.
BTU1
British thermal unit, the amount of heat required to raise the temperature of 1 lb. of water 1° F
Applicable Models
- Models: ALL MODELS