Should a hot water circulation pump run all the time?

08 Apr.,2024

 

Eman85 said:

Doing some reno on my house and putting in a new 40 gallon electric AO Smith WH. Master bath is about a 30 ft run of 3/4" PEX from the WH. Is it worth it to put a recirculation system in? I know having faster hot water to the shower is nice but aside from the convenience does it work out in savings in not wasting water vs running the pump and heating more water?
If it's worth it which style system?

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A button or trigger for on demand to run a set period of time is definitely the way to go. In my last house I had a home automation system (zwave switches and outlets,

A button or trigger for on demand to run a set period of time is definitely the way to go. In my last house I had a home automation system (zwave switches and outlets, homeseer providing control logic/coordination) that provided on demand triggering and it worked really, really well. I had it tied to the light switches in the bathrooms/laundry room and a motion sensor in the kitchen. Turn on any of the lights or detect motion and Homeseer turned on the pump for 30 minutes. My one bathroom/laundry room was about as far away from the water heater as it could be - must have been 80 feet of pipe from the corner of the basement to the opposite 2nd story of the house and it could take literally 3 minutes of running water to get hot water there - what a waste. I'm in a new house on the other side of the country and I haven't gotten around to setting the system back up here yet but it's high on my to do list. I'm also using the watts pump - I just set the timer to be always on and use a zwave outlet to turn it on and off as needed. In my last house I used the under sink returns watts provided to run the return back down the cold water supply and they worked just fine. A little warm water in the cold supply but not too bad. This new house has a return already plumbed in so it's just a few connections to the water heater for the pump and return and I'm good to go. Heck I don't even have to make any connections as everything is threaded. I'm now in the desert - conserving water is a much higher priority than conserving natural gas - but even if I was still back east, clean potable fresh water is still a valuable resource and not nearly as plentiful as people assume.

What You Should Know About a Hot Water Recirculating Pump

Hot water is a modern convenience that most of us typically don’t think much about. However, if you have ever had to wait several minutes for the water coming out of the faucet to heat up, you may be interested in learning more about hot water recirculating pumps. Rather than only sending hot water to your faucet when you call for it, these types of systems ensure that there is always a steady supply of hot water ready to come out of the tap right away.

While waiting a few minutes to get hot water is more of an inconvenience than anything else, it can also be quite wasteful. Unless you collect that unused cold water in a bucket to reuse in your garden or elsewhere around your home, it all just goes straight down the drain. With a hot water recirculating pump, cold water sitting in your pipes will go back to the water heater, bringing new hot water to the faucet so that it is ready whenever you are.

Because of frequent drought conditions and water restrictions here in California, the state’s Building Energy Efficiency Standards now require all new homes to include hot water recirculating pumps if they have any faucets that are farther than 50 feet from the water heater. The goal of this policy is to prevent water waste as homeowners wait for the hot water to arrive. Even if your home is older and not required to follow this new rule, it can still be a good idea to make the switch. Here’s what you need to know.

Why Cold Water Comes Out of a Hot Water Tap

When you have separate handles for hot and cold water, you expect hot water to come out of when you turn the hot handle and vice versa. So, why is it that you get a stream of cold water from your hot tap before the water heats up? The answer is that leftover water in the pipes has cooled over time.

When you operated the hot water tap the last time you needed it, the water shuts off as soon as you turn off the tap. However, the hot water had to travel from your water heater to the faucet for you to use. When you turned the tap off, there was still plenty of hot water in transit. With the faucet turned off, there is nowhere for that hot water to go, so it just sits there in your pipes. Over time, it will gradually lose its heat, leaving cold water behind in your hot water pipes.

Then, the next time you turn on the hot water, that cold water in the pipes has to make its way out before fresh hot water can come through. This is the cold water that you feel for the first minute or so after turning on the tap. Once the hot water has had enough time to make its way from the water heater to the faucet, forcing all of the cold water out along the way, you’ll get the hot water you need. The farther the distance between your water heater and faucet, the longer it will take for the hot water to reach you, and the more water you will waste in the process.

Hot Water Recirculating Pump Styles

To minimize water waste while waiting for hot water, you can have a recirculating pump installed on your water heater. These pumps return any unused hot water to your water heater to maintain its temperature while also sending fresh hot water to your faucets so that you don’t have to wait for the water to heat up. Hot water recirculating pumps generally fall into two primary categories.

Full Recirculating Pump System

In this type of system, your plumber will install additional hot water pipes in your home. These pipes can then return the unused hot water to the water heater. As the cooling hot water makes its way back to the water heater, new hot water can take its place so that it is always ready to go when you need it. The hot water flows through a continuous loop throughout your system so that there is a steady supply of hot water, minimizing your wait time and water waste.

If you are concerned about how this constant operation might affect your energy costs for heating the water, there is no need to be. While the system is capable of running continuously, it doesn’t always do this. Most hot water recirculating pumps come with sensors or timers to regulate operation. Sensors can detect the temperature of the hot water in the pipe, only running the recirculation pump when the temperature drops below a specified level. This way, the water won’t keep circulating when the water is already warm, typically stopping itself after one complete cycle.

Timers give you even greater control over when your system operates. For example, you can program your system to automatically turn off after a specified time in the evening so that it isn’t running while you are sleeping. You can also program the schedule to turn the system off when you are at work or go out of town on vacation.

Even if the hot water recirculating pump you choose doesn’t come with a sensor or timer, your plumber can easily install one for you. This way, you’ll get all the benefits of having more control over your system without having to select an entirely new pump system.

During the installation process, your plumber will need to install additional piping throughout your home to carry the unused hot water back to the water heater. This can add to your installation cost considerably, especially if the pipes in your home are difficult to access. If you don’t want to weather the added cost, or if the installation would be too complex, you do have another option.

Recirculating Pump Comfort System

To avoid having to install new pipes, you can opt for a hot water recirculating pump that sends unused water back to the water heater through your cold water pipes rather than through a separate pipe system. This option is much more cost-effective and easier to install, making this style of system accessible to a wider range of homeowners. However, you’ll still get the benefit of fast hot water when you need it.

Comfort systems do come with one major drawback, though. Because the hot water will flow back to the water heater through the cold water pipes, the water that comes out of the cold tap at first will likely be warmer than you are used to. It may also take a few moments for the water to get truly cold. In most cases, this won’t be much of an issue, as lukewarm water is perfectly fine for many applications around the house, like cleaning and cooking. However, if you use your tap to provide drinking water, you may have to wait until the water is cool enough to be palatable.

You can combat this issue when you know you are going to need cold water by turning off the pump temporarily. This method is particularly effective during the summer. Because the weather is warmer during this time of year, you won’t need to run the pump as frequently to get hot water anyway, as the water already in the pipes will stay hot longer.

Saving Water with Hot Water Recirculating Pumps

While the most obvious benefit of hot water recirculating pumps is that you’ll have access to virtually instant hot water from every sink in your home, you’ll also be saving a lot of water. Because there are so many factors that go into calculating the water savings, it is difficult to quantify exactly how much you’ll conserve, though some estimates place the amount as high as 15,000 gallons per year. However, certain factors can increase or reduce your savings.

For starters, the size of your pipes plays a major role. Pipes with larger diameters can carry a lot more water than their narrower counterparts, so you’ll see the greatest savings if you have pipes that are on the wider side. The distance between your water heater and faucets is important as well. If your hot water previously had to travel a long way to reach the tap, your savings will be higher than if your faucets were closer to the water heater.

Choosing Your Hot Water Recirculating Pump System

When choosing your hot water recirculating pump, your first decision should be whether you would prefer a full recirculating system or a comfort control system. Your budget and the configuration of your home will be among the most important factors in this decision. If plumbers can easily gain access to your pipe system and you can afford to pay a bit more, a full recirculating system will give you the greatest benefit, without the drawback of warming up your cold water on the return. To save money, time, and hassle, a comfort system may be the better option for you.

Once you have selected the style of system you would like, your next step is to choose a sensor or timer to control it. If you don’t want to have to worry about programming your system, a sensor can do the job for you by monitoring the water temperature in your pipes. To maximize the efficiency of your system, though, you’ll want to have the greatest possible control over when your system operates. For this, you’ll need a timer.

Simple, mechanical timers are easy to install and even easier to set. However, you may be limited in how detailed you can get with your timing. If your schedule changes from one day to the next, an electronic timer will give you greater flexibility. You can typically program several scenarios to accommodate changes in your daily schedule, like from workdays to the weekend or if your schedule doesn’t follow the typical work week.

Other Considerations

It is also a good idea to insulate your hot water pipes, both heading to your faucets and back to the water heater. This will help to trap heat inside and prevent it from dissipating through the walls of the pipes over time. With proper insulation, the water will stay hotter for much longer, minimizing the number of times you have to run your pump throughout the day to keep hot water in the pipes at all times. This can result in major energy savings over time.

California is known for having hard water, and if you don’t have a water softener installed in your home, the minerals in the water can wreak havoc on your hot water recirculating pump. To help it last as long as possible, look for pumps made from stainless steel to minimize the risk of corrosion and prevent calcium deposits from forming.

You should also take note of the size of the inlets and outlets. As calcium deposits form in the pipes, they can narrow these openings over time. The larger the opening, the easier it will be for water to continue to flow through. Even with a bit of buildup, you’ll still have plenty of water coming through, maximizing the amount of time between maintenance services.

Learn More about Hot Water Recirculating Pumps

Here at Best San Diego Leak Detection, we are proud to include hot water services among our offerings. This includes installing, maintaining, and repairing water heaters and their associated accessories, like hot water recirculating pumps. We are experts at what we do and can help you narrow down your options to settle on the best recirculating pump to meet your needs and budget.

Our friendly associates are always happy to answer your questions, so don’t be shy about reaching out if there is anything you don’t fully understand. We’ll set you up with a free consultation appointment to discuss your needs and preferences in greater detail. Call now to get started.

July 16, 2019 Categories:

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Should a hot water circulation pump run all the time?

Hot Water Recirculating Pump: What You Should Know