We just bought a whirlpool cabrio washer and dryer from a couple who had it in storage for a year. It worked fine last night when we tried it for the first time, then this morning when I was washing sheets it stopped during the wash cycle and displayed error "F51". The manual says when you get an "F" error message to press the '"pause/cancel" button once then "start" again. It starts, then immediatey displays the same message. We have tried cancelling the cycle and starting over, a different wash cycle, even unplugging it, but it keeps happening. The washer fills up just fine, but then when it's time for the agitator to start, that's when we get the message. Help!