Block Heater Buzzing

I installed a new block heater in my truck about two weeks ago. I noticed an audible buzzing from under the hood of my truck today while out clearing snow. It went away as soon as I unplugged the block heater. As far as I can tell it's still working and it's not popping the breaker on the house. Is it safe to plug it back in, or did I get a bad one? I've never had a block heater buzz before, anyone experienced this?

I did some further research on the net and it would seem that it's not terribly common, yet not unheard of for a block heater to emit some sort of buzz or hum. I'm gonna go with it unless I find some other reason not to.

I always figured it was the water sizzling around it. There's not really anything to "buzz" since its really just a big resistor.

I always listen for a light buzzing sound to be sure it's working. It's normal.

Sheldon

Normal

Normal and nothing to worry about.