13 flashes could indicate the thermister on the top of the drum has a problem. The most common problem is a break in the wire going to it (due to vibration). We can test your module for you for free (postage back is £6) and even supply you with one if it is faulty. See our site at www.emwelec.co.uk Tony EMW Electronics
www.emwelec.co.uk, February 2012