What they do well
Endless hot water, a much smaller footprint, and a longer service life than a tank if they are maintained. For a household that runs out of hot water on a busy morning, the difference is real.
Where installs go wrong
A tankless unit burns far more gas at peak than a tank does. Drop one onto a gas line sized for the old heater and it will short-cycle, throw ignition faults, and never satisfy two fixtures at once. Most of the disappointing tankless installs we are called to fix were undersized on gas from day one.
The hard water problem
Scale builds in the heat exchanger faster here than the manual assumes, because North Texas water is hard. A unit that is never descaled loses output and eventually faults. Budget for that maintenance or budget for a shorter life.
Venting and condensate
Condensing models produce acidic condensate that needs somewhere to go, and every model has its own venting requirements and clearances. These are not optional details, and they are the ones most often skipped.
Whether you should
If the gas can be sized properly and you will keep up the descaling, a tankless unit is a good buy. If neither is true, a well-chosen tank will make you happier. That is the answer, and it does not depend on what is on the truck.
Questions about any of this on your own property? (940) 231-5706 reaches Norman Alambar directly, Texas Master Plumber M-44741, working Krugerville and seventy-five towns across North Texas.
Call Norman direct
Tell me what it is doing and I will tell you what it takes to fix it.