Nine months ago I replaced the valves in my shower myself. Recently, I started noticing that when I first turn the water on to take a shower, there is a distinct smell of mold. This has never happened before. It really seems to be coming from the water itself. (It's not the drain.) After a couple of minutes it goes away. I am planning to remove the shower head and even take the valves back out if necessary.

Could I have done something wrong when I installed the valves?

There is also a slight mold smell inside my washing machine, which is on the same floor. This is also new. I have run loads with bleach, but it doesn't go away.

Sounds like you may have some bacteria growing in there.
Remove the shower head and soak it in bleach over night. Reinstall it and try it for a few days. If the smell returns then we may have to do the same thing to the valve. But I'm hoping this will get it. Good luck, Tom

Tom got it, you can also soak the shower head in vinager, if the smell comes back then we will tell how to clean the shower valve, Thanks.

John

Many thanks!
I will try this.