Circulating pumps are the life blood of the plantroom. They act as arteries, helping to bring vital HVAC and water services from the plantroom to intended recipients and locations.

Heating, air conditioning and water services are distributed in a building by circulating pumps. A twin pump set (two pumps) are generally utilised to provide continuity of service – should the duty pump fail, the standby pump enables – ensuring no downtime or interruption to critical HVAC and water systems.

Given their importance, pumps are periodically inspected and tested as part of planned preventative maintenance (PPM). A facilities, building or maintenance manager can also check the operation of a pump without the need for tools. A useful app, created by Danfoss, conveniently and precisely informs you if a pump is operating. The video below shows the app in use, transparently displaying that the twin pump set was operating as intended.

Danfoss Magnetic Tool app

While the app can’t replace the intervention and knowledge of a service engineer, it does perform the following three functions for facilities managers.

1. Transparency

A pump’s operation can be checked by merely downloading the app and holding your phone over the pump to confirm operation and direction.

2. Energy and operation

As shown with the twin pump set in the above video, the app will show pumps that are not in operation (stand-by pumps). Energy waste could occur if standby pumps were operating without the need for them. The app also indicates the direction of a pump – giving you the precise magnetic field rotation of the pump. Pumps operating in the reverse or incorrect direction are forced to work harder and therefore are less energy efficient.

3. Time

A check on pump operation with the app can aid the swift diagnosis of a faulty pump. Providing this information to your maintenance contractor before they arrive can potentially aid a quicker repair.


High and low pressure switches

The video also displays the repair of high and low pressure switches, which previously were not working correctly or safely by immobilising boiler and pump plant, as intended. These switches were designed to protect the capital value of your equipment in a safe and efficient manner.

High pressure switch

The high pressure switch activates when it detects a failure in the heating expansion system. It protects the boiler by ensuring it doesn’t fire, further adding pressure to the system by heating water and increasing expansion. While best practice dictates that pumps should continue to operate to dissipate heat in the system, rather than ceasing operation completely. Depending on installation specification, some pumps may be wired to shut off in the event of a high pressure switch activation.

Low pressure switch

The low pressure switch activates when it detects a leak in the system. It protects the boiler by ensuring it doesn’t fire or top-up the system by introducing fresh water into a closed system. The switch also protects pumps from burn out, in the event of low pressure by ensuring they do not operate.

Download the Danfoss Magnetic Tool application

Planned preventative maintenance (PPM)

PPM of circulating pumps should take place as part of a building’s complete HVAC and water services system due to their interconnecting parts. PPM is a proven cost-effective solution, providing comfortable conditions that support your business needs. Unmaintained systems will eventually fail to function, become troublesome or perform at levels that are inefficient. View further information on HVAC and circulating pump maintenance.