How can I fix my Fisher & Paykel dryer?

We have enjoyed our Fisher & Paykel clothes dryer (Model DE08) for the past 2.5. years. However, of late, it has been speeding through the timed cycles, taking four and five re-sets to dry the clothes. And now, it doesn't seem to be getting hot enough to dry them. I have already totally dismantled the exhaust and vacuumed out everything, so there doesn't seem to be any clogs anywhere. Could this be a problem with the timer switch? I have replaced these before in other dryers, with great success. Please advise. Thank you.