Identified themselves as Clear View....something about energy efficiency updates.

I answer all calls and waste their time.

I answered the call only to hear the "boiler room" noise and no voice.  I asked, who is this?  The answer came back in profanity.
Whoever this is needs to be stopped.

Caller stated they were offering to upgrade my home to make it energy efficient.  I asked him what he was selling and he what was I looking for?

Had bogus Caller ID. Didn't waste my time with answering.  Blocked number.