Water Heaters - Rumbling Noise

Troubleshooting noise issues for Electric and integrated Electronic Mixing Valve (EMV) Water Heaters:
 
NOISEPOSSIBLE CAUSESWHAT TO DO
Rumbling noiseWater conditions in the home caused a buildup of scale or mineral deposits on the heating elements.The heating elements need to be removed and cleaned. This should only be done by a qualified service person or plumbing contractor.
Squeaking/Chirping sound when drawing hot water (EMV models)In certain usage conditions, noise may transmit through the plumbing from the integrated mixing valve.Increasing user set point or lowering capacity setting may address this condition on integrated mixing valve models. Consult a plumbing professional to install a pressure limiting device, if due to high water pressure.
Intermittent EMV motor noiseA soft motor noise may be heard during normal operation due to movement of the control valve.This noise is normal and does not indicate any issue with the unit.