A core requirement under BS 7593:2019 is that central heating systems are tested annually, to help maintain system health and to identify and rectify any issues before they cause damage to the system. The Benchmark Commissioning Checklist further supports this practice to evidence the correct servicing and installation of boilers. The onsite Express Inhibitor Test makes compliance with these industry

With the initial dose, its key to make sure the system water is circulated properly so that the inhibitor is sufficiently mixed. Fernox recommend that you let the system circulate for at least 15 minutes. Also having the system on hot will help speed this up.