Rheem RTGH-68DVLN-3

The 123 therms figure is calculated by this site, not by the registry. It combines the registry's UEF, the ratio of hot water delivered to energy used, with the DOE test's daily hot-water draw for the medium pattern. For this model the UEF is 0.9. The registry record comes from the DOE CCD, retrieved 2026-09-19. The 123 therms figure holds only at that test draw. A household using more hot water each day than the medium pattern assumes would use more gas than this figure. A household using less would use less gas. The data does not show how far real household use differs from the test draw. The method is set out on the page explaining how the annual cost is calculated.

Among the 80 gas tankless models registered at the medium draw pattern, this one has the 10th lowest annual energy use. Its maximum flow rate in gallons per minute is 3.5. The comparison fits a household whose daily hot-water use is close to the medium pattern and whose demand at any one moment stays within 3.5. It fits less well when several outlets together call for more than 3.5. It also fits less well when daily use is well above the medium pattern. In that case the 123 therms figure and the 10th rank describe the test, not that household. The data cannot say how often a given home goes over 3.5. To compare models by fuel, space and size, use the water heater selector.

This page does not give a running cost as text. The cost is 123 therms multiplied by the average residential gas price in the reader's state, so the page works it out from the reader's ZIP. The same applies to the 12 therms gap to the class median. What that gap is worth depends on the reader's own gas rate, and this text does not state a figure for it. Both values appear in the cost calculator for your own ZIP. The installed price range is in its own block on this page, with its source and date. It is a modeled installed-cost range, not a quote. To check other units registered in the same class, use the same-class replacement search by model number.