Do you have this valve installed for your washer supply? If not, get off the computer, call your service tech, and have one installed immediately.
Shutting off the valves that feed your washer when not in use is by far the best and most reliable way to extend the life of your washer. Factory installed shutoffs on the machine are not anywhere near as durable as WATTS brand mixer valves. It is a solid piece of brass, more durable than the plastic hardware that comes stock in your washer. And the ease of shutting off all water to your washer after finished, you can't beat it. The installation is completely worth it.
Take a look at what supplies your washer now. If you see any corrosion, green dust, or moisture, Get one of these installed. Your washer connection is also the most priominent of valves failure in your home. Get it done!