What is an Immersion Heater?

An immersion heater is an electric heating element that is installed inside a hot water tank, used primarily to heat water. It acts much like a giant kettle, using an electric resistance heater (which converts electricity into heat) to bring the water to a desired temperature. Immersion heaters are particularly useful as a backup water heating method or in situations where other forms of water heating are not available.

How Does an Immersion Heater Work?

Immersion heaters work on a simple principle: the heating element inside the heater is completely submerged in water, and when electricity passes through it, the resistance in the element generates heat, which is then transferred directly to the water.

Typically made from copper or stainless steel, the immersion heater’s element is sheathed and often includes a thermostat which allows for control over the temperature to which the water is heated. This thermostat not only helps in maintaining the water temperature but also prevents overheating, enhancing safety and efficiency.

Most immersion heaters are installed through the side of a hot water cylinder. They can be used as the sole source of heat or in tandem with a boiler. This setup is especially common in homes where a boiler heats the water during the day, and the immersion heater serves as a supplementary heat source or takes over during the night.

Immersion Heater – How to Use?

Using an immersion heater is straightforward, but it’s important to operate it correctly to maximize efficiency and safety. Here are the basic steps:

1. Check the Setup: Ensure your immersion heater is correctly installed and that all components, including the thermostat and electrical connections, are in good working condition.
2. Set the Thermostat: Before turning the heater on, set the thermostat to your preferred temperature. For most households, setting it between 60°C and 65°C is adequate to provide comfortable hot water without wasting energy.
3. Switch On: Immersion heaters typically have a dedicated circuit and switch on the household’s electrical panel. Make sure you turn it on only when you need hot water, as keeping it running continuously can be quite costly.
4. Monitor the Water Temperature: Once you switch on the immersion heater, it will take some time for the water to reach the set temperature. Be mindful of the heating time and avoid overheating the water to save on electricity.
5. Switch Off When Not in Use: To save energy, turn off the immersion heater when hot water is not needed, especially during extended periods of absence from home.

How Much Does an Immersion Heater Cost to Run?

The cost of running an immersion heater depends on several factors, including the unit’s wattage, the cost of electricity in your area, and how efficiently the heater and your hot water cylinder are insulated.

Here’s a basic breakdown to help you understand the potential costs:

• Electricity Costs: Check your local electricity rates, usually charged per kilowatt-hour (kWh). As of 2021, the average electricity rate in the US is about 13 cents per kWh.
• Heater Specifications: The wattage of immersion heaters typically ranges from 1 kW to 3 kW. The higher the wattage, the faster the water heats up, but the more power it uses.
• Usage: The amount of time the heater is on will significantly impact your energy bill. For example, running a 3 kW heater for one hour a day at the rate of 13 cents per kWh will cost about 39 cents per day, which translates to approximately $11.70 per month.

To reduce running costs, consider the following:

• Insulate Your Water Cylinder: Proper insulation keeps the water hot for longer, reducing the need to frequently reheat water.
• Use Off-Peak Electricity: If your electricity provider offers lower rates during certain hours, take advantage of these times to heat your water.
• Regular Maintenance: Periodic checking and maintenance of the thermostat and heating element ensure your immersion heater operates efficiently, preventing excess energy use.

Final Thought

Immersion heaters are a reliable and straightforward solution for heating water in your home. Understanding how they work and how to use them efficiently can help you manage your energy consumption and maintain consistent hot water supply, ensuring comfort and savings on your energy bills.