What does "nd" mean?

I have had this in the past and have found the drainpipe block. The usual place is right at the end, nearest the sink. This appears to be the narrowest point of the pipe line. Just undo the drain pipe at this point ( with a small drip tray under to catch the drips) and clean both the drain pipe and the tee section in the sink side of things. Good luck

Craig
December 2007