The hot water faucet leaks when I use my washer.
I have turned the faucet off, but it still leaks.
Only when the washer is in use. It is leaking from
the neck not the spout. If that makes sence. What
should I do?

RickJ

When you say "the neck" are you speaking of the stem that the handle is attached to?

If so, that's a simple diy project. You need "stem packing". Here's an explanation with illustration.:
http://www.thisoldhouse.com/toh/tvpr...696574,00.html

speedball1

Rick gave you very good advice along with a picture of a faucet, (see image) He correctly identified your problem as a water leak at the bonnet packing nut. Try this, open the faucet up a bit and when the water begins to leak past the stem snug the bonnet packing nut up untill the leak stops.
If that don't get it then you may need to replace the bonnet packing itself.
Good luck, Tom