A tankless water heater does not have a large holding tank for heated water that has been???1Add a comment...High Mark PlumbingShared publicly - 2015-03-18 Expert Plumbing in Langley - What exactly do people mean when they talk about ???plumbing???? The plumbing system in your home or commercial property is a complex configuration of pipes, seals, fittings, tanks and other components that are requ