Why is there a loud humming sound coming from my grill that won’t stop?

The humming you hear is a resonance similar to what you find in a musical instrument. It is caused by small periodic changes of flow across the diaphragm located inside the regulator and is more likely to occur when in high flow conditions. Occasionally, this occurs in regulators, but is not harmful to you or the operation of the product. The sound is not dangerous as long as it is not accompanied by the smell of gas.