Ruud RTG-70XLN-1

The registry does not print the 209 therms figure. This site computed it from two inputs. The first is the model's UEF, the ratio of hot water delivered to energy used. The second is the daily hot-water draw that the DOE test sets for the high draw pattern. DOE CCD lists a UEF of 0.81 for the RTG-70XLN-1 at that draw pattern, retrieved on 2026-09-19. The result holds only at the test draw. A household that draws more hot water each day will use more gas than 209 therms, and one that draws less will use less. The data does not show how far real use may differ from the test. The steps are set out in how the annual energy and cost figures are calculated.

This model is compared with the 397 models registered as a gas tankless unit at the high draw pattern. It ranks 323rd for lowest energy use out of 397. That places it in the highest quarter of its class for energy use. The high draw pattern describes a larger household, or one where showers and laundry overlap. Its maximum flow rate in gallons per minute is 4. It fits a household that matches that pattern and needs no more than 4. It fits less well where lower gas use at this draw pattern is the goal, because most models in its class use less than 209 therms. Models from the same class can be listed with the same-class replacement search by model number.

This text does not give a yearly running cost for the RTG-70XLN-1. The cost is 209 therms multiplied by the reader's state average residential natural gas price, and that price differs from state to state. The page works out the cost from the ZIP you enter in the running cost calculator for your own ZIP. The 27 therms gap above the class median of 182 therms applies only at the federal test's draw. What that gap costs in a year also depends on the local gas price, so the data here cannot give it. The installed-cost range on this page sits in its own block with its source and date. It is a modeled range, not a quote, and this text does not restate it.