Ariston's Aures Luxury electric instant water heater, priced at $299, is designed by Italian designer Umberto Palermo and` is developed with the brand's Constant Temperature technology and other features, such as the Anti-Scalding System 2.0.

What a water heater does is pretty self-explanatory — it heats water and supplies that hot water to appliances in your home, most commonly, the shower. However, purchasing a water heater is not that straightforward, and one size doesn’t fit all. There are a number of considerations to think about, including knowing what type and size of water heater suits your family, and home, as well as practicality and aesthetics. 


Generally, there are two types of water heaters — storage and instant. 

Storage water heaters

A storage or tank water heater provides a ready reservoir of hot water to be used.

It consists of a storage tank that holds up to over 100 litres of constantly heated water that can be dispersed throughout your home. When turned on, cold water is heated and stored, and reheated until needed. The storage water heater releases hot water from the top of the tank, and allows cold water to enter from the bottom of the tank to be heated, ensuring that the tank is always full. Since water is constantly heated, energy can be wasted, even when you are not using the water — so remember to switch if off after use!

For storage heaters, you have the option of electric-, and solar-powered models, as well as digital and heat pump ones. Heat pump and solar storage water heaters are eco-friendly choices, as they make use of renewable energy sources. A heat pump water heater takes heat from the surrounding air and transfers it into the tank to heat up water using a compressor.

Heat-pump water heaters, such as the Frankie from Ariston, are an eco-friendly chocie, as they efficiently heat a large quantity of water using a low consumption of energy by absorbing heat from the surrounding air.

“Instead of using typically around 3000W of electricity, it uses only about 250W — meaning electricity savings of up to 75 per cent!” says senior country manager Eddie Lee, of Ariston.

The latest models in the local market, however, are digital ones, which come with digital control panels that give you more control over the heater, making more efficient use of electricity to save energy.

Digital water heaters, such as those by American brand A.O. Smith, are equipped with control panels that allow you to adjust the thermostat to save energy.

Those by A.O Smith, available at AOS Bath, even come with a patented automatic energy saver, which is a memory chip that records your family’s usage habits to allow them to operate with the highest efficiency and lowest electric cost, says Amanda Zhong of AOS Bath.

A storage water heater can be installed in the ceiling (concealed with a false ceiling, for example), cabinet, basement or garage. 

Instant water heaters

An instant or tankless water heater heats water directly on demand, without the use of a storage tank.

When you turn on the tap, water is rapidly heated to the desired temperature, as it flows through the unit’s heat exchanger. Energy is only used when the instant water heater is being utilised, which translates to more savings in the long-run. However, these type of water heaters generally have a higher initial cost.

For instant water heaters, you have the option of electric and gas. 

Gas water heaters from City Gas are designed with built-in safety features and are also tested to EN26 standard by TUV SUD PSB Singapore, an established and internationally recognised product-testing corporation.

According to information on City Gas’ website, based on an energy study conducted by Dr. Lee Siew Eang, an associate professor at the National University of Singapore’s department of building, gas water heaters are relatively more environmentally-friendly with 63 per cent less carbon emissions as compared to electrical heaters. City Gas is Singapore’s town gas and natural gas utilities provider, and offers a wide range of gas water heaters, including those suitable for Housing Board flats.

As there is no water storage tank, it is also a space-saving option. Instant water heaters can be quite compact in design, and are commonly mounted on the wall, close to the point of use — for example in the shower area. But since it is exposed, it will definitely affect the aesthetics of your bathroom!



This is important, because it greatly affects your showering experience, and the look of your bathroom.

Water pressure might be an issue with instant water heaters, as the unit’s output limits the flow rate to about three to four litres per minute.

“Flow restrictors are built into every tankless system, to enable water to be heated instantly when it flows through the heater, but this results in reduced water pressure,” says Amanda. These restrictors ensure that temperatures up to 39 deg C can be reached.

For instant water heaters, water temperatures might not be consistent, as the temperature is dependant on water flow rate, which is also affected by others users in your household.

On the other hand, storage water heaters supply water that has already been heated, allowing a high-pressure flow of about 10 litres per minute, and with temperatures of up to 70 deg C. If you’re partial to very hot showers, this is something to note.

So, it is best to stick with regular hand showers if you have an instant water heater. In comparison, storage water heaters can support almost any type of shower fixture, from rain showers to massage jets, and bathtubs.

In short, instant water heaters give you hot water on demand, but at a lower water pressure and wavering temperature consistency, while storage water heaters give you better  water pressure and consistent temperatures — but the amount of hot water available at the point of use is determined by the size of the tank.

Ariston Aures Round Smart is an electric instant water heater that has a contemporary and minimalist appearance. It also features the brand's Constant Temperature technology.

However, there are exceptions, thanks to new technology. Ariston’s Aures electric instant water heaters are equipped with the Italian water-heating brand’s Constant Temperature technology, which maintains a constant water temperature throughout your shower while letting you have instant heating. It also has a more contemporary design and a less obtrusive appearance.



Conventional storage water heaters are normally concealed because they are bulky and unpleasant to look at, so you need to cater space for its installation. For the new HDB Build-To-Order flats, the HDB has already designated a place for the storage water heater.

Electric storage water heaters, such as those from A.O. Smith, are typical, and usually have a capacity of around 30 to 100 litres.

The amount of space required to house the water heater depends on the size you are going for as well. “The most popular size for storage water heaters in Singapore apartments is 40 litres, which can fulfill the needs of an average family of three to four people,” says Amanda. 

The Ferroli Macro MA-10FE gas instant water heater from CIty Gas is a suitable model for both single-point or multi-point continuous usage in HDB flats.

Instant water heaters are wall-hung, and can be installed at any point in time. This makes them a good option for residences that are rented out on short-term leases. Depending on water usage, your home may need more than one unit. 



Instant water heaters typically have a lifespan of five to seven years, while storage water heaters last at least 10 years. It is recommended that you perform tank flushing every five years for storage water heaters, and check the wiring every three to five years for instant water heaters. 


Interested to find out more about water heaters? Here's another great read: Choosing the right size and type of water heaters