The Pros and Cons of Instant Hot Water Recirculating Pumps

Nothing in life is ever cut and dry. There are always going to be some advantages and disadvantages.

Take a hot water recirculation pump.

You want instant hot water when you turn on the faucet. At the same time, you may feel like it saves water and money, but does it really?

How much do the best ones cost? Is the installation expensive?

You’ve got questions and I’ve got the answers.

In this article I will highlight everything you need to know about recirculation pumps. There are several options to getting instant hot water so you need to understand which one will fit your needs best and if it is even worth it to buy one.

Watts 500800 Recirculating System

Programmable:
Yes

Type:
Above Heater

Voltage:
120V

Easy Installation:
★ ★ ★ ★

Price:
$$

Check it out!

Laing LHB08100092 AutoCirc

Programmable:
Yes

Type:
Comfort System

Voltage:
115V

Easy Installation:
★ ★ ★ ★

Price:
$$$

Check it out!

Grundfos UP15-10SU7P/TLC Comfort System

Programmable:
Yes

Type:
Comfort System

Voltage:
115V

Easy to Use:
★ ★ ★

Price:
$$$$

Check it out!

How does a hot water recirculation pump work?

Think about how things go when you don’t have a pump.

Your tank heats your water to the temperature that you like. But, it doesn’t pump the water to your faucet until you turn it on. So, that water sitting in your pipes from the tank to your faucet ends up cooling to the ambient temperature.

Now, you turn on the hot water and wait for the heated water to finally arrive. In some cases over a minute, which then washes all that water down the drain.

With a recirculation pump, the idea is that there is a flow of continuous hot water through the pipe so there is no wait for hot water. It is already hot at the point of arrival.

How does this work? Different units work differently, but the idea is that the pump keeps the hot water moving through the pipe where it either ends up back to the boiler with a dedicated line or there is a system in which the hot water runs through the cold water pipes.

I’ll go over the way different ones work in a bit.

Do recirculating pumps save money?

This isn’t an easy question to answer. They definitely can save money, but it depends on what kind of pump and how it is used.

How much water do we waste by waiting for the hot water? Let’s say it takes a minute for your water to arrive to the tap or shower. If you are using low flow fixtures, you just dumped at least 1.5 gallons down the drain with the shower and 2 gallons at the kitchen sink.

Add that up over a year and you can see how much water is wasted.

So, if you waste say, 10 gallons of water per day, that adds up to at least 3,650 to 5,000 gallons per year. And that is a very conservative estimate.

But, that only adds up to about 8 or 12 dollars per year.

So, they won’t save you much money unless you have a huge family, in an enormous house with the furthest fixture more than 100 feet from the water source.

If you just hate the thought of wasting water and not counting the cost, then the good news is that it does save water.

What about the electricity to run the pump?

This is where what kind of pump you get really matters. If you have the traditional one that is basically pumping water all the time, then you are actually costing yourself money in the long run. They don’t typically use a lot of electricity as they are very small pumps, but they certainly are not saving money.

The basic answer, is no they won’t save you money.

I still think they are worth it, but first let’s talk about the different kinds because this will make a big difference.

Types of recirculating pumps

There are essentially two different kinds of recirculation pumps that you will likely to be looking into.

Traditional Full Recirculating and Under Sink Recirculating Pump Comfort System.

Both have their pros and cons, but understanding each of them will help you decide which one is going to be right for you.

Traditional Full Recirculating

For many years this is what you likely would have gotten if you were looking to get instant hot water to your fixtures. In fact, many hotels around the world use this system for the convenience and comfort of their guests.

This pump be placed over the boiler will circulate the hot water from the tank to your faucet. At the furthest point from the boiler, you’ll need a dedicated hot water line that runs back to the tank, creating a perfect hot water loop.

Now, that doesn’t mean that you’ll have hot water circulating 24 hours a day through that line. Almost all recirculating pumps these days will have a timer on it so it only starts the recirculating at the hours when you’re likely to need the instant hot water.

What makes this a not so attractive option for people is that it requires some additional plumbing to bring that loop together. You’ll need a plumber to run a considerable length of pipe and hook everything up. This can add a lot to the installation costs.

Under Sink Recirculating Pump Comfort System

This is the most likely option that many of you will be looking at. In fact, from this point on I will only be referring to this type of pump as the other is not a great option for most people.

The way this one works is that the pump is installed under your skin, or at least close to the point of use. Instead of needing a dedicated line that loops back to the boiler, this one has a sort of connector that runs between the hot and cold water lines at the outlet. It has a toggle that will open up when the pump is running that allows the hot water to pass through to the cold water line when the faucet is not open. Then the water cycles back to the boiler through the cold water line.

These types all work on timers, too so it is only on when you are home so it isn’t pumping water through the lines when nobody needs it.

The downside to this version is that since hot water is entering the cold water line, then when you want cold water, you have to let the water run a bit to flush out the warm water.

Tankless Water Heaters with Recirculating Pump

A sort of third option is to have a tankless water heater that comes preinstalled with a recirculating pump or is at least ready for one to be added.

If you aren’t familiar with a tankless water heater you can read up on the pros and cons of owning one to see if it is right for you.

This is a great option to have as you are not only heating water only when you need it, but it provides endless hot water that arrives at your preferred temperature instantly.

For many people having a tank boiler system is grossly inefficient and would rather have a tankless that provides endless hot water. One of the downsides is the wait for the water to heat which is solved by the recirculation pump.

They are not a great idea for everybody so make sure you click the link I provided to the article and read it carefully before deciding to go for a tankless.

Installation Costs

How much does it cost to install a recirculation pump? It can end up costing as low as zero dollars if you get an under sink recirculating pump and install it yourself.

This is a big reason why I suggest this type of pump over the traditional over boiler ones that require a plumber to run a dedicated line. Unless you can do that yourself it can cost quite a bit to hire a plumber. And even if you do it yourself, you are going to have to pay for a long length of piping and material.

An under sink one can be installed in a matter of minutes. The only thing you may need to pay for is a power source if you don’t have any outlet near your point of use.

Here is a video to show just how easy it is to install.

The unit you get will likely contain all the hoses and connectors so you won’t be out of pocket by needing to buy all that stuff separately.

Should you buy a recirculating pump system?

If you are like me, then you hate the thought of wasting water.

So, even if you don’t really need the comfort of having instantaneous hot water, the idea that you aren’t dumping water needlessly down the drain is reason enough for buying a recirculating pump.

For everybody else who needs some creature comforts, then having hot water as soon as you open a fixture is the height of comfort and once you have it will never want to go back to washing hands in cold water to avoid wasting water.

No, they won’t really save you any money in the short or long term. And, they do need to be put on a timer to keep them from running all day and night. Which can be inconvenient when you want hot water at a not predetermined time.

The cost of a recirculation pump is not that much and installation is easy enough to do it yourself, so it is an easily afforded luxury that at the same time will make your house less wasteful of our precious natural resource.

Do you have any questions about these pumps or any other water system for your home?

Let me know by dropping a comment in the box below. I love getting questions and comments and am here to help!