Hoover AAA Whisper: Error Number 3?

My washing machine is Hoover AAA Whisper. It won't drain. The little computer message says ERROR 3. So I've cleaned out the filter but it didn't need cleaning. I've also poured a couple of bottles of Mr Muscle plughole unblocker down the corrugated pipe that's suppose to be the draining pipe. I hoped that when I put on a hot wash cycle with no washing in, it would clear the pipe, but it's still not draining. Now I've got the drain pipe full of chemicals and no way to get it out, and a washing machine that's not working. Any ideas PLEASE.