i installed the Pixie last Monday, Tuesday it worked fine for the programmed 10 min sprinklers, but this morning it marked as finished but kept on watering. I tried the manual shut off and on and discovered i had to reduce the water pressure for it to work. At full pressure i hear the noise that the valve is trying to close, but it fails. The light goes to green and the water keeps running... 

For now i am adressing it by reducing the water flow, but is this normal? I just have regular city water, nothing special, no special pressure...?