A circulation pump is a device that ensures the movement of water circulating within a system. Circulation pumps are essential for closed-loop heating and cooling systems, helping to maintain the flow of liquids in boilers, water heaters, and similar equipment. In heating systems, they overcome resistance in the piping and deliver heated water to radiators or other heat emitters. The selection of a circulation pump is crucial for heating systems, as it functions like the heart of the system, ensuring liquid flow even to the most distant points. Circulation pumps are commonly used for heating and hot water circulation. Their use has allowed modern heating systems to operate more efficiently, reduce pipe diameters, and provide higher efficiency at lower temperatures. By maintaining a small amount of heated fluid in the pipes, the water does not cool, ensuring consistent heating and improved system efficiency.
What Is the Purpose of a Circulation Pump?
The primary function of a circulation pump is to move water through the system. It plays a critical role in overcoming the resistance of the piping so that heated water reaches heat-emitting devices. Key benefits include:
- Reducing water waste: Since a circulation pump ensures there is always hot water available, it prevents unnecessary water loss.
- Energy and cost savings: In spaces where constant hot water is not required, circulation pumps prevent fluid from accumulating in pipes, saving both energy and money.
Circulation Pump Installation
To install a circulation pump:
1. Clean the piping if the system is new.
2. Use heat-resistant gaskets during installation.
3. Ensure the pump’s flow direction points toward the boiler.
4. Connect the pump to an electrical panel that supports its maximum flow rating.
5. Set the desired pump stage.
6. Proper grounding of the electrical system is crucial.
7. For cooling systems, protect against freezing and ensure insulation.
8. If installed in lower areas like basements, consider a drainage pit or use a drainage pump to prevent water damage.
Circulation Pump Selection Factors to consider include:
- Type of fluid (e.g., hot water, steam, heated oil)
- Application purpose and location
- Required flow rate and discharge height, which determines how much water must circulate to heat the building efficiently
- Compliance with relevant standards
How to Remove Air from a Circulation Pump
Before filling the system with water:
1. Check radiators, connections, valves, and radiator caps, tightening any loose parts.
2. Air trapped in the system can prevent proper heating and cause noise.
3. To release air, turn the plastic part of the bleed valve and open it downward. Have a container ready as water may spurt out.
4. If the pump makes noise or the system is not heating properly, inspect the entire system. Issues may include a blocked pump, worn bearings, or trapped air. In some cases, replacing the pump may solve the problem; in more complex situations, a full system check is recommended.