How Does a Hot Water Recirculation Pump Work?

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There must have been instances where you turn on the hot water tap, and the first thing that came out was cold water. You may have been forced to wait a short while before hot water starts running. Not only is this frustrating, but it is also inconvenient.

How Does a Hot Water Recirculation Pump Work?
How Does a Hot Water Recirculation Pump Work? (source)

This happens when hot water gets to the pipes, and it has to push the existing cold water out before coming out. If you are one of those people who have ever experienced/experiences, this do not worry.

There is a solution, and it includes installing a hot water recirculation pump.  Let’s dig deeper on recirculation pump, how it works, and much more.

What is a Hot Water Recirculation Pump?

Before we get to the dynamics of how it works, you need to understand what is a hot water recirculation pump. It is a special type of pump that ensures hot water is instantly available at the point of consumption.

As earlier stated, when you open a hot water tap you will have cold water running out first. This is caused by the unused hot water that you left the last time that cools after staying in the pipes. Recirculating pumps avoid this by returning unused hot water back to the heater.

How Does Water Recirculation Pump Work?

Let’s first subdivide the pumps into two categories to help you understand. The two types of pumps are;

  • Full Recirculating Pump
  • Recirculating Pump Comfort System

Recirculating Pump Comfort System

Here the system uses the existing cold water pipe to return cold water to the heater when the tap is closed. Such a system can help people who are usually frustrated by having to wait before getting hot water.

It is even cheaper compared to the full recirculating pump. It is highly effective in cases where one’s heater is far away from the point of use, like the shower or kitchen faucets.

Advantage of Using a Recirculating Pump Comfort System

  • Low Installation Cost – when purchasing this type of pump, you do not have to buy an additional pipe. This is because it uses the same one that carries cold water. With this, you get to save a lot of money while still getting exceptional results.

Disadvantages of Using a Recirculating Pump Comfort system

  • Lack of Cold Water – since one pipe is used for both taps, the cold faucet may start letting out Luke warm-water. In some cases, you may find that the water may take some time before it gets cold.

Full Recirculating Pump

When installing this particular pump, you have to adjust your plumbing system. The changes involve adding a new pipe that will handle how water only.

Meaning after the step is complete you will have two pipes, one that has cold water and the other that runs hot water. With two pipes, a loop is created, which runs from the taps to the heater and then back again.

So how does this system work? When unused hot water is left in the pipe, the pump draws it back to the heater through the loop. Therefore, when you need hot water, it is availed to you quickly through the loop’s hot water pipe.

I know you may be wondering about the energy costs. Isn’t it costly to have the heater run continuously as the water is looped endlessly? I know this is one other many questions ringing in your head right now.

Well, the answer is, not necessarily. This is because there are mechanisms to prevent the process from going on when not in use.

One of these mechanisms is a sensor. With a sensor, the machine shuts off when hot water has made a complete loop. This means that once the job is done, the machine stops working, and you do not have to waste electricity.

Many recirculating pumps also come with timers. Timers help you control the instances when you want the machine to be active.

Advantage of Using a Fully Recirculating Pump

  • Both Pipes Work independently- meaning will not get lukewarm water via the cold water tap. Neither will you have to wait for the water to get cold, unlike in the recirculation comfort system.

Disadvantages of Using a Fully Circulating Pump

  • High Cost of Installation- here, you will have to purchase an additional pipe. This is an added cost on top of everything else which might dent your wallet.

Benefits of Recirculation Pump Systems

At this point, you have a vivid picture of what a recirculating pump system is and how it works. Let us look at the benefits that come with having one.

  • Reduces Wastage of Water – without this pump, when you open a hot water tap, cold water runs first. You must let the water run out before you can get access to hot water. As you let the cold water run out without being collected, it goes to waste. With a recirculation pump, the story is different. Hot water is available right when you request it, and no water is lost/wasted.
  • Saves Time – opening a tap without this pump forces you to wait a couple of seconds before getting hot water. You may have to wait a little longer than a few seconds if the heater is far from the house. A recirculation pump solves this particular issue. By availing hot water instantly, it saves a lot of time that can be used to complete other tasks.
  • Convenient – with this pump, you do not have to be frustrated about dealing with cold water first. As soon as you turn the hot water tap, you gain access to hot water immediately. In essence, it makes everything run smoothly.


Recirculation pumps are great for delivering hot water instantly. With such a system in your home, you get to save a lot of money and time.

Let us not forget that the convenience comes with using a recirculating pump. Using a recirculating pump saves water, is convenient, and saves time.


This is George, the Aquaman, editor at AquaMantra. I'm a water quality analyst by profession, and used to work at one of the largest water bottler company.
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