The operating principle is generally the same for all instant water heaters. These are compact appliances that offer a heating output that is high enough to heat up incoming cold water while it flows through. Unlike traditional heating systems, a cylinder is not required.

Depending on the type of appliance, instant water heaters may vary in regards to heating element technology, operation, equipment level and control concept. These factors have an effect on convenience and efficiency. Instant heaters that are electronically controlled can save a high amount of water and energy costs in comparison to hydraulic water heaters.

Lower Energy Costs

Instant water heating units are required to operate when there is a need for hot water. This lowers energy costs substantially every year. These units are also highly energy efficient with high energy ratings.


A properly sized unit can effortlessly deliver an ongoing supply of water when temperature levels are preset. This can be a number of gallons of hot water every minute with the assurance that they never run out of water.

Long Life and Versatility

Instant water heating systems feature an impressive life span and longer life expectancy that can cover decades. Compact sizes take up less space than a conventional heater. Their versatility makes it possible to fix the water heaters virtually anywhere in the house.


Instant water heaters attain high scores in terms of safety. Their high level of safety is attributed to the fact that their operation is limited to the demand for hot water. This is unlike storage types of units that are always on.

Modern water heaters consist of numerous features that further enhance their safety. Monitoring systems, for example, provide details about water flow and pressure. In case the system fails, the machine instantly turns the instant water heater off.


  • Instant water heaters are designed to provide hot water when it is needed. Unlike storage water heaters, they do not produce standby energy losses and can save you money. They heat water directly without using a storage tank.
  • When you turn the hot water tap on, cold water goes through a pipe and either an electric element or gas burner heats the water. This process results in the water heater delivering a constant hot water supply. You do not have to wait for a storage tank to be filled up with an adequate amount of hot water.
  • Applications for instant water heaters include boosting solar water heating systems, appliances like dishwashers and for remote hot tubs or bathrooms.

Choosing a Water Heater

Before purchasing a water heater, it is important to consider the size, fuel type, energy factor or efficiency and costs.


Installing and maintaining a water heater properly can optimize energy efficiency. Installation is affected by various factors, including safety issues, building code requirements, climate and fuel type. It is advisable to hire a qualified heating and plumbing contractor to install your water heater.


Regular maintenance can have a positive impact on the life span of your water heater and reduce loss of efficiency. The owner’s manual typically contains helpful information about maintenance recommendations.   

Published by Harris Scott