For the past month we have been experiencing a damp odour whenever we use the washing machine. It doesn't seem to be coming from inside the machine itself; it starts when the water is turned on. This is the only place we get this odour.
Answer:
I'm suspecting that you don't keep the lid of the machine open when it is not in use. Try that because the odours tend to build up that way. If I'm wrong, dump a tablespoon full of bleach into the machine before retiring it for a load because its the residue water in there that's causing the odour.