Replacing the water inlet valve in a Whirlpool Duet GHW9150PW0 washer
Un-plug Power Cord from Wall Outlet.
If water continues to enter, bad Water Valve.
click on picture
The hot and cold water inlet valves are located at the back of the washer.
Water Inlet Valve #1 in diagram
Source: Procedure for replacing fill valve on Whirlpool Duet GHW9150PW0