fix a washing machine - Fisher Paykel GWL08?

Hello, We have a Fisher Paykel washing machine. It's been a fine appliance but recently strange things are happening. During cycles the cold water valve opens allowing water into the tank. Even if we open the lid, it continues to flow, the only way to stop it is to turn off the water inlet tap. I thought it might be the solenoid/valves sticking or hanging up, so I purchased new hot and cold valves and installed them. That did not fix the problem. Any suggestions? Thanks, JB