Question
The letters I see on the controller are IR05 means nothing to me. I realize it is very old, why would the controller not shut off at all on the first section? I can manually operate it and shut it off. Do I need to replace the controller?

Answer
Hey Peter, I'm not sure I exactly understand the question, but let me try this. First un plug the controller, Does the zone (valve) stay on? If it stays on with the controller un plugged, then the problem is in the valve. If the valve stays on when you plug the controller in, then the controller is faulty and needs to be replaced. Good luck and have a great day.