How Does A Hot Water Recirculating System Work?

Tankless recirculation system lg

One of the most tedious parts of a regular hot water faucet is the wait. You have to wait a few seconds or minutes before hot water erupts, depending on the size of your home and the length of the pipes. You tend to waste a lot of water as you wait for hot water. So, what’s the solution?

Hot water recirculation systems provide near-instant hot water access, so you don’t have to wait for the water to heat every time you use a faucet or appliance. A hot water recirculation system creates a loop between the water heater and the faucet, and unused water quickly loops back for reheating.

When you think of it critically, you realize that we waste a lot of water and time waiting for hot water to drip from a faucet. Studies show that a person wastes 30 gallons per day unknowingly. That said, with recirculation systems, you can save energy costs. Let us see how this pump works.

How Does A Hot Water Recirculating Pump System Work?

One of the reasons hot water delays when you turn on the faucet is the distance it travels. Remember, the water needs to travel through long plumbing pipes before you use it. Also, the unused water remains in the lines. Therefore, the faucet will first receive cold water then hot water when you turn on the heater.

Generally, the hot water recirculating system is a pump that creates a loop that retains hot water in the pipes. You could be wondering what happens when the pump is not in use? In essence, you have to unplug this pump during vacation or when you move houses.

As it is, there are two types of hot water recirculating systems:

1. Conventional Hot Water Recirculating Systems

It is always on, so you’ll always have instant hot waterHarder to install in an existing home
You can install an on/off timer to save moneyMore lines and parts which can be harder to repair
It has a dedicated return line to the water heater

In the conventional hot water circulating system, one pipe carries the hot water. It circulates water to the far bathroom or fixture and back to the water heater. At the same time, the circulating pump pulls the water from the outermost installation back to the water heater. In the process, the pump creates a loop.

The water circulation in the pipes is a continuous process that allows hot water availability when you need it. Some of the hot water recirculation systems come with timers to set the hours it operates. That saves you energy costs.

The other types of hot water recirculation systems have a few differences from this one. For instance, the next one does not have a dedicated hot water pipe.

2. Instant Hot Water Recirculating System

It is not constantly on, so it wastes less energyYou usually have to turn it on manually
Easier to install in an existing homeDoesn’t have a dedicated return line to the water heater
Very minimal maintenance and repair needs

Since instant hot water recirculating systems do not require a dedicated return line, they are easy to install even in retrofits. This type of hot water recirculation pump comes in two varied versions:

One version of the pump is situated over the water heater, and it has a check valve under the sink that’s outermost from the heater. Usually, the hot water recirculation pump will push the hot water through the valve located under the sink. This will, in turn, create the hot water loop.

You can choose to run the water heater loop using a timer or leave it plugged for the entire day. While using a timer, the hot water loops run only during hours you want them to, usually when you need hot water.

The check valve connected under the sink most extreme from the heater helps complete the loop around your house. The water heater requires power to run, so you should install it near a socket.

This entire system comes with all the components you need to install at home. The great thing is that instant water heaters need minimal maintenance. Furthermore, you may install them with practically all manner of plumbing pipes.

Even so, the instant hot water pump pressurizes water directed to the cold side every first time. For that reason, the far-away sections will receive warm water initially. But you shouldn’t be worried so much about that. Because the hot water then comes gushing in almost immediately.

This type of hot water recirculation system relies on human intervention to turn on. In a sense, you need to turn it on when you need hot water. The previous version we discussed above either runs constantly or is controlled by a set timer.

Still, there are some similarities as far as functionalities are concerned. For instance, it can have a valve under the outermost sink from the water heater or have a specific pipe to carry the hot water. The idea is to provide water when needed throughout your entire home.

Once you turn on the recirculation system, it pressurizes the cool water in hot water lines and returns it to the heater. In the process, it will create a loop just as the waters heat up.

Instead of the cold water running to waste as you wait for the hot water, it is maintained in the loop as it goes back to the water heater.

Typically, this heater will shut off once the hot water is hot enough (reaching the required temperature). It allows the hot water to run out through the faucet instead of making its way back in the loop.

This system runs well because once it detects hot water at the pump, it immediately shuts off and stops hot water from entering the cold pipes.

Starting up this system is relatively easy. You may switch a button or run it using a wireless remote within your home. How cool is that? Some advanced systems even have motion sensors that detect the water flow. Depending on the water flow, they may automatically turn on or off.

Are Hot Water Recirculation Systems Efficient?

under sink water recirculation lg

One of the selling points of the hot water recirculation system is that it is efficient. It’s better than the regular hot water system as evidenced by the following benefits:

Saving Time

If you have a standard hot water system, you could be surprised to know that you save time with the hot water recirculation system. It might not be much, but as a whole family, you get to save awful lots of time.

Can you imagine how boring it is to stand there waiting for hot water to run? I get the feeling. And it is not just showering even when you need to wash your hands, especially in the cold weather. It is okay to pull a stunt in the icy water, but the feeling isn’t mutual for most people.

Since you are part of the regular folks, the hot water recirculation system is a lifesaver.

Saving Water

The hot water recirculation systems save a lot of water. One study revealed that an average person wastes about 1-3 gallons of water as they wait for hot water. And if you think of it, the farthest fixture might be quite a long distance for the plumbing pipes to cover.

You waste a lot of water each time you turn on the shower or faucet and wait for several minutes for hot water. Individually, the average cost of waste might not be astronomical, but it is wasteful, especially when considering the environmental impact of this action.

The hot water recirculation system comes with a timer or sensor to set it during the hours you need to use hot water. For instance, you may put it to turn on in the morning and evening hours when you or family members usually take showers. Or you could set it to turn on when most people are at home.

Saving Money

A hot water recirculation system installation will save you money. The truth is the amount may not be much if you consider the initial cost set up, but it’s worth noting. Additionally, the maintenance costs may also tally with the little that you save from installing the system.

Even so, it makes more sense in the long run. You get to save a substantial amount if you rope in the family usage over long periods. And this is quite significant if you and your family and heavy hot water users.

What are some of the disadvantages of installing a hot water recirculation system?

Cons of Installing a Hot Water Recirculation System

It is worth noting that all appliances have both pros and cons. For the hot water recirculation system, efficiency is a significant advantage that outweighs most of the disadvantages we’ll discuss below.

Initial Set Up Costs

The purchase cost could rise to $400. If you factor in hiring a plumber, the total costs may go up to $1000. However, if you are up for it, you can DIY the installation because the process is pretty simple. You can do it in under 30 minutes.

Research shows that the cost of hot water is the second biggest spending after air condition in American domestic energy usage.

Lukewarm Water

There are two varieties of hot water recirculation systems. If you get one that does not have a dedicated hot water line, there’s a brief moment you get lukewarm water. This may occur for sections most far from the water heater.

But all the same, the lukewarm water is not cold water, so you can consider it a tradeoff. Plus, you may choose to install the other type of system. A hot water recirculation system with a dedicated circulation line is ideal for new construction.

.As a side note, some of the other cons are specific to maintaining the hot water recirculation system installed. Some users complain that their systems sensor valves need changing after every two years.

Some brands don’t install sensor valves directly in the pump. This might call for an entire pump replacement in case of any sensor damage.

Maintenance costs are unavoidable when it comes to domestic gadgets. It would help if you didn’t worry about the minor issues because most will crop up after you’ve used it for a particular period.

How Long Do Hot Water Recirculation Pumps Last?

Generally, a hot water recirculation system will last between 10 and 15 years as long as you use them per the manufacturer’s direction.

Of course, you need to conduct regular maintenance on the pump as required.

The variation in the number of years you can use the pump depends on the daily water usage, the quality of water, and the quality of the pump itself. Different brands offer varied attributes.

Are Hot Water Recirculation Pumps Worth the Investment?

In the long run, hot water recirculation pumps are worth the investment. For one, the advanced technologies in use allow for great timing. Furthermore, considering that the devices will last more than ten years make them worthwhile.

Even with a high initial cost, it is a good investment. The hot water recirculation pumps are easy to access in your local hardware stores. Most people purchase them online through the various online shops or brick-and-mortar shops that sell online.

When it comes to operations, the recirculation pump is relatively easy to operate. First of all, the installation process is accessible while the functions are just a touch of a button. With advanced systems, you get a remote control system located in various sections of the house. So you can turn it on whenever you are in the place.

Again, since this idea is about creating an environmentally friendly product, it also integrates renewable energy. You can seamlessly integrate your water recirculation pump with solar or wind energy if installed in your home.

That way, you save more on energy costs at home.

If you have new construction, you may consider it in the final plans. All you have to do is to select the most suitable fit for your retrofit or new construction.

How to Choose the Best Hot Water Recirculation System for You

To choose the best hot water recirculation system, you need to consider the following factors:

Is It A Retrofit Or New Construction?

If you have a unique building, you have an opportunity to include a recirculation pump with a dedicated line. A dedicated line requires new plumbing lines to be installed, which means the initial setup costs might increase.

However, if you only need one for retrofit, then a dedicated line pump is not necessary. Once you factor in the prices for either retrofit or new construction, it’s easier to plan for the installation.

The Cost

All hot water recirculation systems are not made equal. Just as various companies are offering the product, so does the quality vary. However, because of standardization, the price may vary slightly or with designs.

Nevertheless, consider quality yet pocket-friendly pumps for your home. You also need to consider the ease of use. Does it come with a motion sensor or timer? Does it have remote control access for ease of use around the home?

It is better to pay more for advanced technologies. Also, search for easily integrated renewable energy sources if you use one at home.

The lifespan may vary depending on how you use and maintain the pump, and it’s good to know the lifespan upfront. That allows you to estimate the cost in the long run. This can be bundled with the warranty to ensure the pump doesn’t die on you in the second year. Otherwise, periodical maintenance will ensure you enjoy its services for longer.

Final Thoughts

Hands down, the hot water recirculation system is better than a standard water heater. Once installed, it allows for quick access to instant hot water without water wastage. The loop created means that water is circulating through the pipes from the water heater to the fixtures and back.

Even though the initial setup cost might be high, you have an excellent system for the entire family in the long run. It is a tradeoff when you consider longevity.

The two types of hot water recirculation systems have minimal differences. They work in an almost identical way.

The significant difference is that one has a dedicated hot water line while the other doesn’t. The dedicated line is best suited for new construction. All in all, getting a hot water recirculation pump is worth every penny. Go ahead and get one if you haven’t already. It will save you time and money in the long run.

Of course, it helps if you learn how to DIY-install the hot water recirculation system because it will save you installation service money.

When running a recirculation system with a storage tank water heater, you’ll need an expansion tank. See our article Tankless Water Heater Setups that Require Expansion Tanks.



Hubert Miles | Licensed Home Inspector, CMI, CPI

Hubert Miles is a licensed home inspector (RBI# 2556) with more than two decades of experience in inspection and construction. Since 2008, he has been serving South Carolina through his company, Patriot Home Inspections LLC. As a Certified Master Inspector, Hubert is dedicated to providing his expertise in home inspections, repairs, maintenance, and DIY projects.