An immersion heater is an electrical heating element typically made of metal, such as copper, immersed in a water tank, often found in hot water cylinders. When connected to a power source, the immersion heater generates heat, raising the water temperature in the tank.

Types of Immersion Heaters
Direct Immersion Heaters

These heaters have direct contact with the water in the cylinder, making them ideal for heating the primary water supply. They can be smaller, single-element cylinders.

Indirect Immersion Heaters

Indirect heaters are located within a separate chamber inside the hot water cylinder, separated from the water by a coil or an intermediary fluid. They are commonly used in larger, multi-element cylinders and are often associated with solar thermal systems and heat pumps.

The Role of Immersion Heaters in Hot Water Cylinders
Immersion heaters can rapidly heat the water in the cylinder, ensuring a readily available hot water supply.
In systems where alternative heating sources, such as solar panels or heat pumps, may not be sufficient, immersion heaters serve as a reliable backup. They kick in to maintain the desired water temperature.
The latest immersion heaters come with energy efficiency in mind. Some feature digital controls, timers, and thermostats to optimize energy consumption and prevent overheating.
Immersion heaters are relatively easy to install and maintain. Should a heater become faulty, it can be replaced without replacing the entire cylinder, which can be cost-effective.
Tips in Choosing Immersion Heater and Hot Water Cylinder
Check the immersion heater for signs of corrosion or scale buildup. These issues can reduce efficiency and longevity.
Adjust the thermostat on your immersion heater to your preferred hot water temperature. I can help conserve energy and prevent scalding.