Immersion heater – what should you consider before buying one

Buying or replacing an immersion heater sometimes becomes a very critical decision, especially if the region where you live either has extreme weather conditions or unpredictable climatic changing conditions. In either case, the requirement of heated water for various applications becomes a fundamental and essential need.

However, while doing so, you must ensure that all the details, facts, and verified reviewed data of your requirement vis-à-vis the available options and types of water heaters are appropriately assessed.

Since a water heater is one of the essential appliances required in a home, choosing an immersion heater that suits your needs becomes critical before purchase and installation.

Among the many kinds of water heaters available in the market today, electrically operated immersion water heaters with storage capability are pretty helpful in a home environment.

Immersion heater

What is an immersion heater?

These water heaters comprise an electrically activated heating metal device or element immersed in the water to heat it. This element gets heated and, in turn, heats the water.

Let’s look at the various aspects that need consideration before deciding on buying an immersion water heater for your home.

Immersion Heater Capacity Assessment

You must calculate the capacity of the water required in your home, especially from the point of view of heated water. After that (and as per your hot water needs), plus with a small margin to cover wastage, you should decide on the capacity of the water heater.

While doing so, it is critical to understand the weather and climatic conditions of the region in which you will install this water heater. Severe winter conditions generally mean a much larger capacity of heating and so on.

How Much Does an Immersion Heater Cost to Run?

For a water heater to be energy-efficient, it is essential for the heat generated by the immersion heater element to remain within the storage tank for more extended periods. This sometimes can consume higher energy, i.e., electricity.

Therefore, it is imperative to ensure that the energy rating of the water heater is based on the rating levels as laid down by the authorities. At times, however, utility rates and the cost of heating water using an electrically operated immersion water heater could appear to be higher than the cost of a gas-fired water heater.

But, if a proper assessment of the Life-cycle-Cost is done, then it becomes clear that the cost difference invariably tends to get overstated by not considering the efficiency of these water heaters. This then becomes the total cost of ownership assessment.

Immersion Heater Pressure

Water pressure is one of the critical factors to consider before deciding on installing a water heater. If you live in a high-rise building or tower, water pressure in the inlet water mains must be first known.

Generally, as a rule of thumb, consider a rated pressure of more than 6 bars. In such cases, ensure that the water heater has a pressure control valve installed. This valve releases overpressured water to avoid tank damage or leakage.

Water Type

A lot of immersion water heaters have been seen to corrode and rust over a while. After the assessment, it was known that this happened due to the water quality being fed into the water heater. This factor generally tends to get overlooked.

Many localities have been receiving hard water. This type of water tends to cause scaling on the heating element and inside the storage tank, causing short circuits and leakages. Hard water is also not suitable for continuous human use unless filtered and treated appropriately to remove or reduce the hardness.


These are safer than fuel-fired water heaters since they avoid the hazards and problems associated with using a combustion method to heat water. They do not emit any flammable vapours which fuel-fired water heaters could release.

Maintenance & Service

Compared to any other type of water heater, the immersion type of water heaters requires very little maintenance, especially when compared to the Fuel-fired kind of water heaters. Also, these do not require any periodic checks and adjustments or special servicing.

Therefore, considering all the upsides and downsides, you, as the home user, can make an educated choice.

Immersion-type water heaters have certain advantages over the other types, in that it becomes a kind-of lifesaver for you if your home does not have a gas supply line. You must remember, as with all other home appliances and equipment, if used correctly, these water heaters can be very efficient and environment-friendly.

Plus, you could also save on costs.