Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Disappointed

There is nothing in the manual that indicates there is an incline adjustment which is located in the back. The heart monitor doesn't seem to work all the time and there is a trick to where you place your finger which is over the heart shape versus the round circle. Finally the treadmill speeds up uncontrollably and after a while may shut off. They are sending me new control boards and heart monitor to see if that fixes the problem. Their tech will come over and install the parts.They installed new control boards and it still had problems. I was impressed that they offered to replace the treadmill without me asking. Good customer service.