How Does a Cold Water Booster Set Work?

Cold water booster sets are plumbing systems comprised of pumps, tanks and valves that increase a building’s water pressure to meet water supply demands, ensuring that each water outlet has a reliable flow of water.

This guide explains what cold water booster sets are, how they work, components that you would usually find in commercial cold water booster sets and the benefits they can bring to your business. We’ll also cover installation considerations, potential issues to be aware of and relevant UK regulations.

Cold water booster sets help to transport water from the supply pipe to outlets throughout the building. They are particularly important for larger buildings such as schools, hospitals, university campuses and offices, where water demand is high or variable.

Head over to our heating and plumbing services page if you’d like to enquire about cold water booster set design, installation or maintenance.

Why Are Cold Water Booster Sets Important?

In larger buildings, the mains water supply can sometimes struggle to meet the high water demands, as dozens of outlets draw from the same supply. This is particularly true in older properties where the historic (or pre-existing) pipework infrastructure was not designed to cope with modern water usage, or in high-rise buildings where gravity works against the flow of water.

Low water pressure can lead to a range of problems, including reduced water outlet efficiency which can be extremely frustrating for staff and customers, higher utility bills, and compromised hygiene. In settings like hospitals or schools, where consistent water pressure is essential, these issues can quickly escalate from inconvenient to critical.

A cold water booster set addresses these issues by drawing water from the building’s water supply and using pumps to increase the pressure before distributing it throughout the building.

What Is A Cold Water Booster Set?

A cold water booster set is a system made up of pumps, tanks, controls and pressure vessels designed to increase and maintain a building’s water pressure. The system typically draws water from a break tank (cold water storage tank) and uses multiple booster pumps to push the water through the building’s pipework at the required pressure.

When demand for water rises and pressure drops, the pumps automatically start to increase the water pressure to the required level. As demand falls, the pumps slow down. This ensures consistent water pressure throughout the building, even at peak usage times or on higher floors.

Key Components of a Cold Water Booster Set

While the design of cold water booster sets varies depending on the building’s size and water pressure requirements, most commercial systems include these core components:

Break Tank: Also known as a cold water storage tank, the break tank provides a stable reservoir of water that feeds the booster pumps. An air gap between the incoming mains water supply and the stored water prevents backflow and contamination. This ensures that the system adheres to The Water Supply (Water Fittings) Regulations 1999.
Booster Pumps: Multi-stage centrifugal pumps increase the water pressure by pushing water through the pipework. In multi-stage pumps, water flows through multiple chambers that each have their own impeller, so they can increase the water pressure. Many modern systems use variable speed drives (VSDs) that automatically adjust pump speed to match the water demand, which is more energy-efficient than fixed-speed pumps that run at a constant rate regardless of demand.
Control Panel And Sensors: The control panel monitors system pressure, manages pump operation and displays any issues detected by sensors located throughout the system. This allows for faults to be detected quickly.
Pipework: A riser pipe carries water up through the building, connecting the booster set to the building’s distribution pipework and individual outlets.
Non-return Valves: These valves prevent backflow into the pumps, ensuring water only flows in one direction through the system and protecting pumps from reverse rotation and pressure surges.
Accumulator Tank: A pressurised tank located on the discharge side of the pumps. Its main purpose is to balance fluctuations in supply pressure by storing and releasing water as needed. It also allows the pumps to switch off briefly without losing pressure, reducing wear on the system and saving energy.
Water Hammer Arrestors: These chambers absorb the shock caused by pressure surges that can occur when pumps start or stop suddenly, or when valves close quickly.

How Can a Cold Water Booster Set Benefit Your Business?

Installing a cold water booster set can bring a range of practical and financial benefits for your business:

Reliable performance: Even in areas with outdated infrastructure or fluctuating mains water supply, a booster set maintains steady water flow throughout the building, creating a comfortable environment for staff and customers.
Optimised water usage: Consistent water pressure means that all outlets are being supplied with the optimal volume of water, reducing waste. For example, if the water pressure is too low, toilets might need to be flushed multiple times.
Energy savings: Modern systems with variable speed drives only use the energy required to meet water demands, reducing running costs.
Protection for plumbing infrastructure: Stable pressure reduces stress on pipework, helping to prevent leaks and costly repairs.

How to Design, Install and Maintain a Cold Water Booster Set

Design Considerations

Designing a successful cold water booster set requires a careful assessment of several factors about the building: the number of outlets (taps, showers, etc.), peak demand periods and their required water flow rate, the height difference from the water source to the highest outlet, and the available space for tanks, pumps and pipework.

The existing plumbing infrastructure of the building must also be surveyed. If there are any weaknesses or faults that could compromise the operation of the booster set, they will need to be addressed before installation can proceed.

Installation Process

A typical installation involves positioning and connecting the break tank and booster pumps, making any necessary pipework modifications, installing and connecting it to the tanks and mains water supply, priming the pumps, testing outlets throughout the building and monitoring pressure levels to ensure consistent performance.

Ongoing Maintenance

Regular maintenance will keep your cold water booster set running efficiently and safely. This typically includes inspections for leaks and unusual noises, checking pressure settings and pump performance, cleaning any strainers and filters, testing safety devices such as water hammer arrestors and non-return valves, and verifying correct operation of the control panel and sensors.

Our expert team of plumbing contractors can advise on planned preventative maintenance for your cold water booster set.

Regulations and Standards for Businesses

Cold water booster sets must comply with The Water Supply (Water Fittings) Regulations 1999, which set out requirements for preventing backflow and contamination of the mains water supply. The air gap in the break tank and the non-return valves prevent backflow and contamination.

The components of your cold water booster set should also be WRAS approved, as this ensures that you have efficient components that have been rigorously tested, as well as compliancy with The Water Supply (Water Fittings) Regulations 1999. Installing products that are not WRAS approved can breach local water regulations and in some instances can be illegal.

Older buildings that have special architectural or historic interest could be listed. Listed buildings are legally protected against alterations, extensions and installations, so you need to get Listed Building Consent from your local planning authority before installing a cold water booster set. Check to see if your building is listed, as carrying out unauthorised work on a listed building is a criminal offence.

How Much Does It Cost?

The cost of a cold water booster set depends on several factors, including the size, age and water demands of your building, as well as the local water supply.

Other cost variables include the number of tanks and pumps needed, the type of pumps (variable speed drives cost more upfront but offer lower running costs than fixed-speed pumps) and the extent of pipework required. While the initial investment varies, a cold water booster set can deliver long-term savings through reduced water waste and lower energy bills.

Head over to our plumbing services page to get in touch with our team, who can map out installation, maintenance and running costs for your project.

Potential Issues with Cold Water Booster Sets

Water Hammer (Hydraulic Shock)

Water hammer is a shockwave or sudden pressure surge as water slams against an upstream closed valve because of a change in pressure. It can be caused by air pockets in the system, faulty valves or a pump shutdown. Over time, these pressure surges can damage the pipework. Water hammer arrestors are air-filled chambers, which means they can compress and absorb the shockwave after a sudden pressure surge, protecting pipework and preventing loud banging noises.

Pressure Failure

Sudden drops in water pressure may be caused by a faulty pressure sensor, a failed pump, air leaks, blocked filters, incorrect settings or a problem with the control panel. Cold water booster sets are very unlikely to experience pressure failure caused by a drop in water supply; it is almost always an electrical or plumbing problem.

Pumps Not Starting

Pumps may fail to start due to electrical faults such as a tripped breaker or loose wiring, or because of closed valves or an airlock affecting the water supply to the pumps. If power and water supply are both fine, the problem might stem from inside the pump. A conditioning monitoring system is hardware that can be installed on the pumps. The hardware constantly monitors the performance of the pumps by collecting data such as rotor speed, temperature and vibration levels. The monitoring system is able to use this constant stream of data to detect changes in performance before they become problematic for the pumps.

Regular maintenance is the most effective way to prevent these issues and keep your system running smoothly. Find out more about our heating and plumbing services including scheduled maintenance for cold water booster sets.

Conclusion

Cold water booster sets are a reliable solution for increasing water pressure in commercial and high-rise buildings to meet water demands.

With proper design, professional installation and regular maintenance, a cold water booster set improves the efficiency of your water outlets, keeping staff and customers happy. It also reduces utility costs and protects your plumbing infrastructure from damage.

If you’re considering a cold water booster set for your building, or need maintenance for an existing system, speak with our plumbing contractors to see how we can help.

Frequently Asked Questions

Check out some of our most common questions.

What Is A Cold Water Booster Set And When Is It Typically Used?

A cold water booster set is a system of pumps, controls and valves designed to increase and maintain water pressure in a building’s cold water system. It is typically used where mains pressure is insufficient, such as in high-rise buildings, large commercial properties, hotels, hospitals and sites with high or variable water demand, such as leisure centers.

How Does A Cold Water Booster Set Maintain Consistent Pressure?

The system uses pumps and valves with sensors that monitor and adjust water pressure automatically. When demand rises and pressure drops, the pumps increase to the required pressure. As demand falls, the pumps slow down, ensuring consistent pressure throughout the building.

What Maintenance Does A Cold Water Booster Set Require?

Regular maintenance includes visual inspections for leaks, checking and testing the system’s pressure, cleaning filters and strainers, testing water hammer arrestors and verifying that the sensors and control panel are working correctly. Periodic maintenance by a plumbing contractor helps prevent breakdowns and maintain the efficiency of the booster sets.

Why Are Variable Speed Drives More Efficient Than Fixed-Speed Pumps?

Variable speed drives (VSDs) automatically adjust pump speed to match current water demand, using only the energy needed at any given time. Fixed-speed pumps run at a constant rate regardless of demand, which wastes energy during periods of low usage.