How Does a Hot Water Recirculating Pump Work?

A hot water recirculating pump works through a combination of mechanical energy and gravity. It speeds up the flow of hot water to taps and pushes cold water down to the boiler. Recirculating pumps are fixtures in many hotels, hospitals and other fancy establishments, ensuring users of instant hot water whenever they turn on a faucet. Without such devices in place, users would have to wait for hot water to flow out of the taps, which results in water wastage. Compounded, this issue becomes a major concern, especially for heavy users such as large business establishments and facilities in places where water is in short supply.

With recirculating pumps, water wastage is eliminated or reduced, as hot water left out in the pipes is sent back to the boiler for heating. Hot water circulates through the pipes whenever it's needed. A hot water recirculating pump is generally mounted at the farthest sink fixture and is linked to the cold water pipe line. Models for home use are made of bronze to prevent corrosion, since oxygenated water that flows through the pipes could cause rust.

Hot Water Recirculating Pump Operation

Recirculating pumps found in homes are centrifugal pumps that are exclusively powered by electricity. A typical pump has three major components:

  • Support bearings
  • Motor rotor
  • Pump impeller

The motor is the one that makes the impeller spin, which in turn sends and pulls water to the pipes. The impeller is a wheel that has bent blades and works like a turbine. It generates a high number of revolutions when the motor is turned on, sending cooled water quickly to the boiler for heating, at the same time pulling up heated water into the fixture. To protect its parts and components, the motor is wrapped with water-repelling material.

Pumps for home use are small enough to fit conveniently alongside standard plumbing systems, while industrial-use types have motors located separately, usually mounted close to heaters or boilers.

Types of Hot Water Recirculating Pumps

Temperature controlled hot water recirculating pumps are sophisticated systems. Sensors check the temperature of water going down the drain when a tap is turned on. If the temperature of the water falls below a specified level, a solenoid powered valve is activated and sends the water back to the recirculating pump. At the same time, the valve activates a centralized circuit board that turns on the motor of the pump. The spinning action generated by the pump's impeller pushes the water towards the cartridge filtration system where it will be filtered and then to the boiler for heating.

There are also models where you can program the pump to turn on and off on intervals, to ensure that hot water is made available only when needed. These types of pumps also consume minimal energy, which translates to savings for the homeowner. Heat loss in pipes is eliminated, since the pumps are activated only during specified times.

These models of hot water recirculating pumps are setting new standards in the industry; they have very good features that prove to be beneficial for users.