Mike,

My interpretation of her post is that she wishes to replace the intake
valve which is inside the washing machine. This is a solenoid valve which
admits water to the machine. She's on the right track here. She doesn't need
to turn off the water heater and she may be able to turn off the water at
the faucets located behind the washer rather than at the main valve.
Probably a good time to look at the hoses between faucet and washer, also.

Dave M.