Which two types of hot water systems are commonly used in residential plumbing?

The two commonly used types of hot water systems in residential plumbing are direct and indirect hot water systems.

In a direct hot water system, the water is heated directly in the storage tank by the heating element or flame from a boiler or a water heater. This means that when you turn on the hot tap, the hot water is supplied directly from the tank, providing immediate access to hot water. This system is relatively simple and widely used in many residential setups.

In contrast, an indirect hot water system uses a different approach where the water is heated by a secondary source such as a boiler. The boiler heats a fluid, typically water or a glycol mixture, which circulates through a heat exchanger. This heat exchanger then transfers heat to the domestic hot water, warming it without mixing the two fluids directly. Indirect systems can be more efficient, especially when paired with heating systems that operate for long periods.

Both systems offer distinct advantages and applications in residential plumbing, making them the preferred choices for homeowners looking for reliable hot water availability. Understanding these systems is crucial for effective installation and maintenance in the plumbing field.