Electric Water Heater

Overview

An electric storage water heater holds a reservoir of hot water ready for demand, reheating it as needed with immersed resistive elements. The heart of the unit is the Inner Tank Assembly, a steel vessel fused with a glass lining that resists corrosion from constant exposure to hot water. Surrounding it, the Outer Jacket & Insulation is an outer steel shell filled with rigid polyurethane foam that limits standby heat loss and keeps the surface cool to the touch.

How it works

Cold water enters near the bottom of the tank through a dip tube, while hot water is drawn from the top, exploiting thermal stratification so the hottest water is always delivered first. The Heating Element Set assembly carries upper and lower immersion elements that convert electricity directly to heat in the surrounding water. A two-element design heats the upper portion first for a fast initial supply, then switches to the lower element to bring the full tank to temperature.

The Thermostat & Cutoff Assembly assembly senses tank temperature and switches the elements through a snap-action contact, with a manually resettable high-limit cutoff that interrupts power if temperature runs away. Because the tank is sealed and water expands when heated, the T&P Relief Valve discharges if pressure or temperature exceeds safe limits.

Corrosion is held off by the Magnesium Anode Rod, a magnesium rod that gives up its own metal preferentially to protect the steel, it must be replaced periodically as it depletes. Power arrives through the Junction Box, and the Control Board Assembly board adds scheduling, leak detection, and remote monitoring. The Mounting Hardware hardware secures the unit on a stand or wall.