Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Had to send it back twice!

When the unit works, it works great!.Within 6 months I had to send it back since it was no longer creating a mist (was only buzzing).And just not (outside of 1 year) the unit will no longer power up.I am hoping they will cover the repair, otherwise I will just throw this piece of junk away.Also don't forget, you have to pay for the return shipping for repairs. At $15 each time, it adds up!I would suggest going for a different unit they resolve these issues...