Arrived on site to diagnose loud noise on a 2020 Lennox unit. Upon arrival spoke over with client and he started unit running is making loud noise consistently as heat is one on system for upstairs. System Dose heat home up just making loud noise. Had client cycled heating mode on upstairs unit. Inspected unit system was operational. Checked gas pressure and found gas pressure high At 3.9 and adjusted gas pressure down to recommend pressure of 3.4. Cycled system with client twice. System is operational and client was happy noise level was reduce a lot. Cycled system one last time with client to ensure systems operating and that noise level was addressed. Both systems are operational upon departure.