Why Does it Take So Long for Hot Water to Reach the Tap?

Lady having cold shower

Having hot water at our beck and call is something that we take for granted – we twist the hot water tap and expect the heated water to come out within a few seconds. If a few more seconds pass and the water is still cold, it can be annoying and delay our day somewhat. Whether you’re wanting a hot shower or trying to do the washing up, hot water is necessary for a range of reasons, but why is it not instantaneous?


One of the most prominent reasons for hot water not coming on instantaneously is that there is always residual water left in our pipes when we’ve turned the taps off. That means that when we turn the hot tap, the residual water needs to be flushed away, and the heated water needs to travel from the hot water tank to our taps.

Pipe length

Pipework illustration

Another factor is the length of the pipes in our homes and buildings. It seems obvious to say, but the longer the pipes are, the longer it takes for the residual water to be flushed out and the hot water to reach the taps.

As well as the length, the diameter of the pipes are important, as the wider the pipes are, the more water that is required to flush out the residual water from previous usage.


Frost on window

The time of year can also have an effect. In winter, the pipes are obviously colder and the temperature of the water passing through can be lower, which of course increases the amount of time required for hot water to come out of the taps. Also, while the pipes are cold, some heat from the hot water passing through will be absorbed by the pipes, meaning your hot shower might take a little while longer to arrive.


House diagram of heating pipes

If your pipes are made of galvanised piping, this can also play a part in the heating of your water. This is a thicker material than the other popular material, copper, so it absorbs less heat and helps quicken the pace of the hot water.

If you have recently used your hot water, you will notice that if you use the hot water tap soon afterwards, the water will be hot almost instantly, due to the lack of residual water that needs to be removed. If you want to remove the wait altogether for things like washing up, then you can have boiling water taps installed in your home, but they do come at a cost.

The speed of hot water arriving is something that we can have some control over – by insulating our pipes, we can ensure that less heat is lost through the metal and the water is coming out of our taps and showerheads with minimum wait times.



VHL are proud to provide expert plumbing services for customers across London. If your boiler is struggling with producing hot water or you’re looking to improve the warmth & efficiency of your central heating, our friendly team will be more than happy to help you.

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