Katherine – A tankless heater is a tank with a separate copper coil inside. The tank water is piped to the heating system, and it also heats the water in the coil. The coil water is piped to the potable hot water in your faucets. These units are more efficient in Northern climates, because the tank (boiler) must be heated year round. Note that Bob Villa generally wears a sweater in summer, and a snowsuit in winter !
