What Tankless Water Heaters Are and What We Cover

A tankless water heater heats water on demand rather than storing a preheated tank. Cold water flows through the unit, passes over a heat exchanger, and exits at the set temperature. There is no standby heat loss because there is no stored water cooling down between uses. The unit fires only when hot water is needed.

According to Energy.gov, tankless water heaters can be 24 to 34 percent more energy efficient than conventional tank units for homes that use 41 gallons or less of hot water per day. For higher-usage households, the efficiency advantage narrows, which is why proper sizing matters. Oversizing a tankless unit for a low-demand household wastes the installation premium. Undersizing it leaves the household with lukewarm water during peak demand. We calculate flow rate demand before recommending any unit.

In Plano’s hard water environment, the heat exchanger in a tankless unit accumulates mineral deposits at a faster rate than in softer water markets. Annual descaling is not optional here. It is the maintenance step that determines whether the unit lasts 15 to 20 years as intended, or degrades to an inefficient, undersized system within five years. Pure Plumbing includes descaling guidance with every installation and handles annual maintenance for existing units.