Top tips on how to balance commercial hot water systems with TBVs


Hot water systems are vital to commercial and healthcare buildings as hundreds of people rely on instant hot water, whether it’s to wash hands, shower or use for cleaning. This high usage makes it important to ensure the supply is safe for use and delivers energy efficiency. One way to feed outlets safely and sustainably is by installing Thermal Balancing Valves (TBVs) (in conjunction with TMV’s). In this blog, we discuss what TBVs are, the benefits they offer, best practice around their installation and how to select the best solution for your project.

Understanding how TBVs balance a system

TBVs use a thermostatic element that automatically balances the hot water network and maintains a consistent temperature throughout the circuit, by dynamically adjusting the flow rate.

As the temperature gets closer to the set point of the secondary hot water return network – which is usually 70°C, the TBV shuts off to restrict the water from the boiler. Water at higher temperatures is forced to other parts of the system that are operating at lower temperature. This helps maintain overall balance across the network, ensuring all outlets get constant hot water, regardless of how close or far they are from the boiler.

Benefits of using TBVs

While balancing commercial hot water networks, TBVs bring multiple benefits:

  • Prevent stagnation by continuously circulating the water
  • Disinfect the system from harmful bacteria such as Legionella, and reduce maintenance intervals
  • Eliminate hot spikes that not only corrode other components over time but can also cause scalding
  • Hot water is available as soon as users open the tap, which reduces water wastage and improves customer experience
  • Makes the system energy efficient by putting less stress on the boiler

Best practice around the installation and maintenance of TBVs

Thermal Balancing Valves should be installed on returning legs of the pipework to eliminate dead legs of uncirculated hot water. These valves can be installed to a single or a group of outlets linked to the hot water network, for example, a group of basins.

As they are designed to balance the entire hot water network, individual valves should be installed at every draw off area. For example, if there are 100 rooms in a hotel, a TBV should be installed for each room. This will ensure constant temperature across the circulating loop no matter where you are in the building.

One common mistake around the installation of TBVs is when they are placed on the return pipework that is closest to the boiler, to act as a regulating valve. This results in a non-balanced circuit because water does not get forced to areas with a lower temperature. Instead, the boiler has to work harder to spike the temperature to get hot water to areas that are furthest away.

It’s important to remember that although TBVs eliminate temperature spikes and balance the circulating hot water network, Thermostatic Mixing Valves are still required at serving outlets to ensure adequate protection against scalding.

As with any plumbing system, it’s crucial to carry out regular cleaning and servicing of secondary hot water return networks too. The piston and thermostat assembly of TBVs can accumulate dust over time, which can result in inadequate performance. So, we strongly advise that installers keep a record of service timelines, and only use WRAS approved products to clean these components.

doctors washing their hands at a sink

Opting for innovative thermal balancing solutions

When specifying or installing a TBV, it’s important to take performance, ease of installation and maintenance into consideration. Other factors to bear in mind include:

  • Appropriate WRAS approvals
  • The valve should operate automatically
  • Offer adjustable temperature settings from 40°C – 65°C
  • Include an integral disinfection function

At RWC, we have developed a range of Thermal Balancing Valves from Reliance Valves that meet these criteria. Our TBVs reduce the flow of hot water from the boiler as the system temperature increases. But if the water reaches 70°C, a bypass port is opened within the valve to allow an increased flow rate throughout the circuit to disinfect the system.

Covered TBV

Reliance Valves’ TBVs bring other operational, installation and maintenance benefits too.

  • They automatically maintain continuous water flow even when the set temperature is achieved to prevent stagnation
  • Setting the desired temperature requires little to no time, simply set the temperature needed with an Allen Key and the system will automatically adjust
  • The valves can be installed in any orientation to suit the space requirement
  • They come with push-fit and standard FBSP connections to suit installers’ preference
  • They incorporate a dry fit temperature gauge for easy temperature testing and monitoring
  • The valves come with an insulation jacket to save installation time and enable easy access for servicing
  • These valves include an identification tag and removable thermometer that sits within a dry pocket, which helps with repair and maintenance

Bring balance to commercial hot water systems

TBVs play an important role in commercial hot water networks. A thermally balanced system is instrumental in providing optimum performance, safeguarding end-users, and realising energy efficiencies.

RWC offers on-site technical support and best practice installation guidance to help simplify these jobs and achieve optimum performance. So, get in touch with our team of experts who are on hand to help with your next project.

Discover more

Visit Reliance Valves to learn more about our TBVs and other solutions by Reliance Valves.

Richard Bateman Headshot

Richard Bateman

Product Marketing Manager Plumbing and Heating

About the author

A highly experienced and passionate professional, I have over 15 years' experience as a commercial and domestic plumber and hold NVQ Level 3 qualifications from City and Guilds

Since joining RWC in 2015, I began as a technical engineer, utilising my extensive knowledge to provide exceptional support. Currently, I am thrilled to be working with the marketing department as a Product Marketing Manager. 

This role allows me to combine my technical background with a keen eye for market trends, ensuring that RWC's products meet the evolving needs of the industry. With my wealth of experience and commitment to excellence, I am proud to serve as a spokesperson for RWC, sharing our innovative solutions and contributing to the growth of the plumbing and heating sector.