We have a Precor 9.31 tread mill. There has been a series of errors on the thing. Error 27 which is an over current error. Now I'm a big guy but I'm below the max load of this thing. Me and Mrs adjust the belt to stay in the middle of the rollers and we loosen the tension of the belt a little bit. The belt had been put on with a lot of tension. The belt is not slipping when we walk on it and the Mrs can run and have no problems. We lubed the deck just to be sure. It seemed to work fine this morning.