Tank Vs. Tankless Water Heater

A water heater is a device used for warming water for household purposes. It is one of the basic appliances installed in every home. Since heating water contributes to maximum electricity consumption, it is always better to analyze the energy efficiency and size while installing a new heater.

The performance of the heaters varies even with the same type of fuel. For example, the electric pump devices are more efficient in comparison to the traditional electric storage ones. In general, there are two types of water heaters based on the configuration, namely, the tank and tankless ones. Here is a look at the differences between the two.

In a tank or storage heater, the heating system is installed in a special insulated tank. Cold water is supplied to the storage through an inlet pipe and is heated according to the set temperature. The heated water is stored in the same tank until it is withdrawn. In case of a tankless device, there is no storage of hot water. The cold water is heated directly after passing heating coils installed in the unit.

The storage device consumes more electricity to operate than the tankless type. As hot water is heated and stored constantly, the energy consumption is high. In the storage device, cold water is supplied to the tank as soon as hot water is drawn off. Thus, the reservoir is always full with hot water, even when it is not required. Energy is wasted, which is called standby heat loss.

As the amount of hot water in the storage device depends on the size of the reservoir, there are chances of insufficient or excess hot water. Whereas in a tankless device, hot water can be withdrawn constantly. Since hot water is supplied on a demand basis, the tankless type is also referred to as a demand or instant heater.

The tank devices are available with electric, natural gas, and liquid propane fuel. The gas and liquid propane devices are more energy efficient compared to electric models. The primary fuel types used in case of tankless devices are electricity and natural gas.

While purchasing a storage heater, the size of the tank is the major criteria for selection. A smaller tank may not be sufficient to provide the required hot water, while an extra large one may result in energy wastage. Hence, depending upon the requirement of hot water and the size of the family, the correct size should be installed. Since there is no storage in the tankless device, size is not an issue while selecting one.

One word of advice for the storage heater is to insulate the tank properly to reduce standby heat loss and chances of corrosion and rust. Otherwise, continuous water storage may lead to corrosion of the tank and will lower the lifespan of the device. In a tankless device, the sediment filter in the water inlet pipe and regular flushing of the heat exchanger is necessary to prevent cracking.