My filters make a buzzing or humming sound. Are they defective?

This is rare, but is nothing to worry about. Your filters are not defective. A small percentage of people may notice a slight hum or buzz of the filters. This is caused by certain frequencies on the line - most often coming from your utility company (the electrical grid). The particular frequencies are just right to make the filter(s) resonate with them.

You can also check devices/appliances in the house to see if the humming corresponds with a particular device turning on (furnace/AC fan, refrigerator, etc).

This is often alleviated or eliminated by adding more filters. If the hum is very loud, you should definitely add more filters and ensure that all your circuits with plugs have at least 1 or 2 filters on them. There are sometimes other things that can be done as well. Dimmer switches and some other types of lighting can cause a hum. Contact us if you need help with this issue