The Water Container light won't go out on Whirlpool Condenser dryer?

My water container on my Whirlpool AWZ541 condenser dryer got full mid cycle and dryer stopped. I have emptied the water container, cleaned the filter and also the condenser unit, but still can't get it to come back on. If I switch it off at the power, the lights all go off, but as soon as I turn the timer dial the water container light comes back on.

I seem to remember that if the container filled up mid cycle you had to do something in a particular sequence, but I can't remember what and the instruction booklet says nothing about it. Perhaps it was on the instruction video which I was sad enough to watch but have now lost?!?!

Help!!!!