I put in an Irritrol mechanical timer. My problem is it will work fine for a month or so then I get a call from the customer and she tells me that the sprinklers stay on. What is happening is the system will go through all the zones then start over again it won't shut off. I went to the supply house and they can't tell me what is wrong, they tell me to call a contractor, I even called Irritrol and they have no idea what is wrong. I have had nothing but trouble with this timer from the beginning. The funny thing is it will work fine for a while then stop working right.