Arrived at customers home Friday, August 26, 2022. Customer concerned about intermittent knocking noise in basement utility space that could be heard throughout home. Inspected in basement utility room and could find no mechanical issues. Ran close washer upstairs as well as other faucets in basement. Unfortunately I could not find or hear any knocking sound. Spoke to manager about issue and we concluded that if knocking sound was heard again to document details and I have company out sometime next week first thing in the morning.