Stc1000 making humming/beep noises

[milldoggy]

Just hooked up an stc1000 I got from eBay. It makes beeping noises. They seem to cycle with the action, such as when the compressor delay is flashing, the noise changes pitch. My other stcs do not do this. I guess I got one of the cheaper knock offs? This one is 110-220 vac, my others are just 110.

I contacted the seller, but should I turned it off. Should I be concerned it is making noise, any safety issue?

Thanks