A hot water heating system is an appliance that heats water filtered to faucets in a home or office. Hot water heating systems can be fuel-fired with gas or electric, a model requiring a power cable to connect from the electric service panel to the hot water heating system.
The primary job of a hot water heating system is to heat water, but the major appliance also stores water until it is ready to use. The hot water tank has insulation to keep the water at a warm temperature in between heating cycles. Hot water heating systems consist of supply pipes that route cold water to the bottom of the system's tank. The delivery system that heats the water routes warm water to the top.
Hot water heating systems also feature safety valves that open when the water temperature exceeds safe limits. Most hot water heating tanks are equipped with steel or glass-lined constructions to prevent corrosion because rust that develops can produce a hole in the water tank. The bottom of the tank also contains a drain to empty the heater if it is necessary to shut down the plumbing of the hot water heating system without affecting the flow of the cold water.