What is the Heating Time of a Water Heater?

The following are the usual estimated waiting times for storage water heaters.
These are the timings recorded when heating from a completely cold water tank.

Heating time

  • Electric storage: 20 min
  • Digital storage (Gen 6): 2 min
  • Digital storage (Gen 8): 0 min (instant)

Do I have to wait that long each time?

No! If your storage heater is sized correctly, you should get your hot water immediately without waiting. This is especially so if your heater is used daily, as there is usually plenty of hot water still stored in the tank from its last use.

Photo by bruce mars on Unsplash

In fact, having to wait a long time for hot water from a storage tank is a myth. The only time you would have to wait is when you are using your storage heater for the first time, or if you have switched your heater off for several days while going on a long vacation (more than 3 days). In that case, your heater will contain no hot water and hence requires some time to heat up.

Why can digital heaters heat faster?

Digital heaters have sensors built into the tank. These sensors monitor the location of hot water in the tank and push it to users quickly.

Not all digital heaters are built equal, some are more advanced than others and will give you hot water almost instantly, while others will still take a few minutes.

In contrast, conventional tanks rely on the significantly slower process of convection and it takes a longer time for hot water to float to the top of the tank where it eventually gets drawn out for use.



Digital water heaters have the added advantage of a control panel, which allows users to see exactly how much water is in the tank before they step in for that shower.

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