JOHN WOOD T-H3J-DV-N 1**

This site calculated the 180 therms figure; the registry does not publish it. It combines the registry's UEF, the ratio of hot water delivered to energy used, with the daily hot-water draw that the DOE test sets for the high draw pattern. This model's UEF is 0.94. The source is the DOE CCD, retrieved 2026-09-19. The result holds only at that test draw. A household that uses more hot water than the test assumes will burn more gas, and one that uses less will burn less. The registry data does not show how far any particular home differs from the test draw. The steps behind the calculation are set out in how the annual cost is calculated.

The high draw pattern describes a larger household, or one where showers and laundry overlap. The registry lists this unit's maximum flow rate in gallons per minute as 4.7. The class is the 397 gas tankless units registered at the high draw pattern. This unit's 180 therms sits 2 therms below that class's 182 therms median. That makes it 165th lowest of 397, in the second-lowest quarter of its class for energy use. If you want a unit from the lowest quarter, you will need to look beyond this model. A home with a lower daily draw falls under a different draw pattern, so this figure does not apply to it. To check other units in the same class, use find a same-class replacement by model number.

This text does not give the running cost. The cost depends on the average residential natural gas price in the reader's state. The page uses the reader's ZIP to apply that price to the 180 therms at the high draw pattern. To work out the cost for a different location, use the cost calculator on your own ZIP. The installed price range sits in its own block, with its source and date. It is a modeled installed-cost range, not a quote, so it is not repeated here. Both the running cost and the energy figure assume the DOE test's daily draw. To compare units with other fuels, spaces or sizes, use the selector by fuel, space and size.