How does a hotwater recirculating pumpwork

This 3-speed circulator comes with a built-in mechanical timer and Aquastat. The 3 speeds allow it to be used with either a storage tank or tankless hot water heaters. The pump is rated for up to 125 PSI water pressure, with a maximum ambient water temperature of 104°F.

My wife and I have lived in our house 39 years; we are presently using the 4th gas heated water tank (Rheem 4 years old), located in the “under house basement/garage.” I’m investigating having a professional install a hot water recirculating pump on the water heater. Do hot water recirculating pumps work the same with gas heated and electric heated water tanks? Do the ‘pros’ outnumber the ‘cons’ using with this system to get instant hot water?

Hotwater recirculating pumpwithout return line

Hotwater recirculating pumpinstallation diagram

Hot water recirculating pumps work by circulating hot water through the plumbing system, ensuring that hot water is readily available at the tap when needed. It uses temperature sensors to monitor the temperature of the water in the pipeline. Pumps can be run on a timer, triggered by a button or motion, or run all the time.

The term "Cross-Connection Control" is essentially is referring to backflow prevention. The definition of a Cross Connection is "A cross connection is the actual or potential connection between a non-potable substance or source." Local authorities will dictate what types of backflow preventers may not be used depending on the backflow risk and health hazard. Sewer, irrigation, wastewater and residential are the main areas. There are two types of backflow, the first is back pressure where the pressure in the downstream piping is greater than the supply pressure, this is caused by a pump or elevation of water in a high rise building, the other type of backflow is back siphonage which is caused by sub-atmospheric pressure in the water system piping.

Some jurisdictions where water is scarce provide rebates on the purchase and  installation costs of recirculating systems. For example, some cities in New Mexico provide a $100 rebate, while it can go up to $200 for some cities in Arizona.

Various types of backflow preventers exist for different applications and health hazard conditions, check state and other local administrative codes or other regulation on the correct backflow to use. The following backflow preventer types are available in all sizes:

Cast iron may be more durable and longer lasting than aluminum. However, it is not recommended for potable water use since rust can develop in the system. Premium pumps use stainless steel, which combines the durability and longevity of cast iron with the rust-proof quality of aluminum.

Since it doesn’t require a dedicated hot water return line, this is a more budget-friendly option. However, since the hot and cold water share the same pipe, cold water can sometimes come out lukewarm or take time to get cold. This can be a particular concern for homes equipped with an evaporative cooler.

Based on the Energy Information Administration’s Office of Energy Consumption and Efficiency Statistics, heating water is the second largest use of energy in an average home (after space heating and cooling). A recirculation pump can lower the cost by reducing the amount of hot water needed.

A recirculation system considerably reduces the time it takes for water to heat up, providing users with instant hot water on tap.

Hotwater recirculating pumpwith return line

The AquaMotion AMH3K-7 is designed to deliver hot water quickly at all points of use between the hot water tank and the farthest fixture that this pump is insta...

Also called hot water recirculation pumps or simply circulating pumps, these dedicated pumps are connected to the water heater and return unused hot water back to the heater. Their purpose is twofold:

This is a useful feature to have if your household has a peak hot water usage time, so you can limit the power needed for heating water only to peak hours. Timers are also recommended in states where electrical costs come at a premium.

To make your selection easier, here’s a handy chart of the hot water recirculation systems we carry and their ideal use cases.

Recirculating pumps come in a wide variety of types and designs to accommodate different water heaters. Some of the things you should look for are:

Hot water recirculation pumps come in two versions: Three pipe systems with a dedicated return line and two pipe systems that make use of a crossover valve.

Some pumps are equipped with timers, or can be programmed to operate only in periods when hot water demand is high (for example, they can automatically turn on during the morning and shut off during working hours). This cuts down on unneeded heating, and reduces costs and wear.

These use a dedicated hot water return pipe connected to the plumbing system. It creates a loop from the water heater to the different fixtures, and back again. Any unused hot water gets shunted into this loop by the pump, so that hot water is always instantly available instead of being left in the main pipe to get cold.

Hotwater Recirculating pumpwith temperature sensor

Backflow is the undesirable reversal in the flow of water from a real or potential source of contamination back to the potable (or clean) water supply. Consider having a garden hose in a bucket of soapy water at your home, and having backflow event occur causing that soapy water to "backflow" into the drinking water portion of your home. Various types of backflow preventers exist for different applications and health hazard conditions, check state and other local administrative codes or other regulation on the correct backflow to use. The most common are reduced pressure backflow preventer and double check backflow preventer valves. Backflow preventers are primarily used in sewer, wastewater, residential backflow preventer, sprinkler and irrigation backflow applications.

The pump features a 24-hour mechanical timer with 15-minute increment tabs and built-in, non-adjustable Aquastat. The Aquastat will tell the pump to run when it senses the water at the fixture is starting to drop below 85°F and will run for about a minute or so until it reaches 105°F degrees and shuts off. The pump will run about 3 times per hour for less than 5 minutes.

The AquaMotion AMH2K-R is designed for hot water heaters with a dedicated return line. It installs right into the return line near the tankless heater, and does not require power or room under any sink.

The AquaMotion Recirculation Systems are the perfect retrofit solution for hot water quickly. As many homeowners know, you can turn on the faucet and wait for t...

Best hotwater recirculating pump

Before looking at recirculating pumps, note what type of hot water heater you have. Tankless water heaters generally require higher power pumps, and should be taken into account. Most pumps may not have the necessary power to be compatible with upscale gas or electric tankless water heaters.

To reduce heating costs, most full recirculating pumps use sensors to shut off the flow when the hot water has made a complete loop. Some also incorporate timers that allow users to schedule the pump’s operation and shut it off during low-demand hours, such as at night or during working hours.

In addition, all of the moving parts are housed in a “Green Eco Cartridge Design”. It is the only field serviceable and replaceable cartridge available, making maintenance and replacement quick and easy.

Dual Check Valve - Model GF8080, GF8080E - The Dual Check Valve or double backflow prevention valve is basically a stripped down Double Check Valve without shut off valves and test cocks. They are non-testable and are typically used by water companies and installed after a water meter to prevent the meter from running backwards and low protection against backflow. This piece of equipment is the center of controversy with many backflow authorities and should never be confused with Double Check Valves. Check with local authorities for required installation, as most do not recognize these as backflow prevention devices.

But showers are one thing. Imagine cooking in the kitchen, and getting some egg or other foodstuff on your hand. You just need a quick 5-second spurt of hot water to wash off the gunk. Instead, you stand there for nearly half a minute with egg yolk on your hand, waiting for the water to heat up. Meanwhile, gallons of cool but perfectly clean water run down the drain.

The AMH3K-7 is designed for single pipe hot water tanks with no return line. As an under sink model, it is compact enough for most under sink spaces and installs quickly without any pipe cutting required: simply attach to the water hoses at the valve and plug in.

Hotwater recirculating pumpreddit

Tankless hotwater recirculating pump

Having hot water on demand is a convenience that many of us take for granted. Imagine taking a shower on a cold winter morning, and you can instantly appreciate this luxury we have on tap, pun intended.

Atmospheric Vacuum Breaker - Model GFAVB - The atmospheric vacuum breaker is one of the least expensive backflow prevention assembly. The GFAVB is a non-testable unit and are good for back siphonage only for non-health hazard or health hazard conditions. They must be installed downstream from any shut off valves and cannot be under pressure for more than 12 hours. If an GFAVB is used backflow prevention on a irrigation system you must install one GFAVB after every valve for each zone in the system. It must also be installed at least 6 inches (150 mm) higher than the highest outlet in the system (some GFAVB manufacturers, and some local officials, require that they be installed 12 inches (300 mm) higher than the highest outlet). Some municipalities do not allow the use of GFAVB’s. These units will NOT prevent backflow pressure and can only protect against back siphonage.

This pump is for use with single pipe, tankless hot water heaters without a built-in pump. It includes an AM6 circulator,  built-in timer and an AquaMotion ODR valve (for under sink installation).

You can also view our complete selection of hot water recirculation pump kits from AquaMotion and Rinnai, catering to different water heaters, price points, and needs.

Unlike the full recirculating pump, this one uses the existing cold water line and a specially designed valve to return the unused hot water back to the heater.

The AquaMotion AMH2K-R is designed to deliver hot water quickly at all points of use between the hot water heater and the dedicated return line. The built-in pu...

According to the EPA, the average American home wastes more than 3,650 gallons of water per year waiting for hot water to arrive at the point of use. A recirculation system cuts down on water losses by delivering nearly instant hot water for use instead of wasting water while waiting for it to heat up.

The ODR installs at the fixture furthest from the tankless hot water heater and acts in conjunction with a circulator to supply hot water on demand or with a built-in timer on the pump.

Some pumps have manual on/off buttons: these need to be switched on before using the faucet. These pumps are ideal for smaller homes where hot water demand is limited to a few fixtures, such a single bathroom.

A check valve stops water from going back to the return plumbing line. This way, it returns water in the line back to the water heater, reducing the time it takes to reach the faucet.

Other systems use temperature sensors that automatically activate the pump if the water in the line falls below a preset value. These are recommended for larger homes with more water fixtures or higher hot water demand.