A tankless water heater heats water only when you open a hot tap. There is no tank to keep hot all day, so you avoid the standby heat loss of a traditional water heater.
How much more efficient?
The U.S. Department of Energy estimates that for homes using 41 gallons of hot water a day or less, tankless water heaters can be 24% to 34% more energy efficient than conventional storage tank water heaters. For homes that use a lot of hot water — around 86 gallons a day — the gain is smaller, about 8% to 14%.
Sizing is about flow, not gallons
A tank is sized by how many gallons it holds. A tankless unit is sized by how many gallons per minute it can heat, and by how much it has to raise the temperature of the water coming in. Two showers and a dishwasher at the same time is a very different demand than one sink. We ask how your household actually uses hot water and size to that peak.
Gas supply and venting
A gas tankless water heater can need far more gas at full fire than the tank it replaces. If the gas line cannot deliver it, the unit cannot reach its rated output. Tankless units also have specific venting requirements. Both get checked before we quote, not discovered on installation day.
The maintenance nobody mentions
Minerals in water build up inside the heat exchanger over time. A periodic descaling flush keeps the unit efficient and protects it. A properly installed unit has isolation valves that make that flush simple. We can add it to your maintenance visits.
Is it right for you?
Tankless shines in homes that want endless hot water, space back in a closet or garage, and lower standby losses. It is less compelling if the gas line and venting changes would be extensive for a small household. We will tell you which side of that line your home falls on.
Call K&A Mechanical at (757) 630-2069 to talk through your home.
