Definition
The main kinds of residential water heater: a storage tank that keeps a supply hot, a tankless (on-demand) unit that heats water as it flows, and a heat pump (hybrid) tank that moves heat from the surrounding air. Each is sized by household demand and fuel type.
Why this term matters
In plumbing, terminology often points to lifespan risk, leak prevention, and whether repair or replacement is the smarter spend.
Related pages
Trade: Plumbing