Radiators share a pump and connected pipework. A branch with less resistance can take more water than it needs, leaving another short. Balancing adjusts that distribution to the system’s design requirements. The aim is suitable heat delivery, not identical valve openings or identical flow through every radiator.

You do not need to replace a TRV body to understand balancing. Start with flow and resistance and the roles of the controls. This lesson teaches how to interpret an assessment and prepare a useful record; it is not a universal commissioning procedure.

Before any practical work, read the gas boundary and emergency/shutoff guidance. Do not open boiler or electrical covers, loosen pipe joints, change bypass settings or force a valve. Hot water and surfaces, leaks or an unfamiliar system require an appropriate competent person.