Locate the movement
Describe which visible section moves and whether the noise began after nearby work. Include whether wastewater still clears and whether the unit runs longer.
Keep connections intact
Do not loosen supports or joints to compare sounds. A professional assessment can consider accessible pipework and appliance behaviour together before recommending suitable work.
A useful distinction
A pipe can transmit sound through a wall or cabinet even when little movement is visible. Describe where it is heard and where it can actually be seen moving, keeping observation separate from inference.