Hot Water Recirculating Systems
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Hot Water Recirculating Systems

A more efficient hot water circulating pump that only runs when you need hot water and pumps the cold water back to the hot water heater to be reheated.

If you are concerned with dumping water down the drain but don’t want to install a recirculating pump with a dedicated return line there is a product that can help you. You can save money and water by installing an energy efficient hot water demand control valve system under your sink or near your water heater to reduce the time it takes to get hot water and eliminate water waste.

Metlund Hot Water D'mand System

Metlund Hot Water D'mand System is an electronically controlled valve and pumping system that rapidly distributes hot water from the water heater to fixtures in a home or commercial building. This system can operate either with a return line or by the existing cold-water line. The Metlund System pumps cold tap water back to the water heater until hot water flows through the unit, saving otherwise wasted water and shortening the wait for hot water. Because it circulates the water only on demand, this system avoids the energy penalties of continuously circulating systems.

There are three units for systems with longer wait times or systems with return lines.

The S-50 models are designed for smaller homes where the distance is less than 50 feet from the water heater.

The S-70T models are designed to effectively deliver hot water rapidly up to 100 feet from the water heater. They are designed for most residential homes under 3,500 square feet in size. With a dedicated return line this unit can be used with a tankless water heater.



The S-02 models will accommodate larger homes and commercial applications where distance from the water heater and larger diameter piping are factors.

Warranties for the S-70T and S-02 models are 5 years and for the S-50 it is 3 years.


  • Life expectancy 15 to 20 years
  • Less than $1.00 a year to operate 
  • Delivers hot water within seconds to more than one fixture
  • System only operates when there is a demand for hot water
  • Simple installation for new and existing homes
  • Works with all standard water heaters (gas, electric, tankless, or propane)
  • Title 24 Compliance (CA only)
  • "No Sweat" easy installation package available with optional remote control button 
  • IAPMO "Uniform Plumbing Code" approved 
  • UL Listed

How it Works

At the push of a button, the S-Series pumps cold water sitting in the hot water line into the cold water line and back to the water heater. The "off sensor" automatically shuts off the pump and closes the zone valve when hot water arrives at the system. Now you have hot water instantly at the fixture and anywhere else plumbed off of the main line.

The S-50T models are smaller pump systems designed for smaller homes. They weigh 6 lbs. Dimensions are 8" wide, 7½" deep, and 5½" tall. This model is not recommended for gas tankless water heaters.

The patented PDV (Check Valve) is built into the pump housing, reducing the number of external devices. The S-50T models are adequate for runs of less than 50 feet.


There are two ways to plumb in a tankless water heater. The difference is whether the D'MAND System pump is located at the water heater or at the furthest fixture from the heater.

Plumbing Schematics

Activation of D'MAND Systems includes choices of hard wired buttons, wireless remote RF (radio frequency) buttons, motion sensors, and in some cases flow switches. In most cases flow switches are only used in commercial or multi-family operations.

Note: If your home has a Pressure Regulator Valve that acts as a back flow prevention valve, you must have an expansion tank in the system before installing a D’Mand System.

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Comments (4)

Thank you for this wise choice for energy and environment protection. Well presented. Out of votes so buzz and twitter.

We have a recirculating system and it's great in the winter!

I have installed many tankless hot water heater systems but I didn't know about these recirculation pumps. Thanks for the heads up Daniel.

Returning with a vote up for a great home improvement article.