Question
When I started my system this spring ,two of my eight zones did not operate.I do not understand as they worked last fall.Thanks for any help you can offer.
                 Sincerly  John

Answer
Hey John, I hope this helps. Normally, there would be three things I would suspect could be wrong. The first thing could be the wire connections at the solenoids on the valves. Make sure where the solenoid wires connect to the field wires, that you have a good connection. The second thing could be the solenoid itself. These are easy to replace, they just unscrew from the valve body (counter-clockwise). When you take it off, make sure you hook it back up to the two wires that went to the old one. The third thing would be whats called the diaphram. This is a rubber membrane that is inside the valve, that raises and lowers to turn the valve on or off. This also can be replaced fairly easily. If you notice on top of the valve, there will be either screws or bolts that hold the top and bottom half of the valve together. The diaphram fits between the top and bottom half. Once you unscrew the screws (or bolts), the diaphram can be taken out, and a new one installed. When you take the valve apart, just make sure you put the spring back on top of the diaphram, and make sure the new diaphram is turned the same way as the old one. There are numerous manufacturers and numerous valve styles, so it is hard to tellyou exactly how to replace your particular diaphram, without knowing which valve you have. Most valves can be rebuilt without going to the trouble of replacing them, but worse case would be that you would have to replace the whole valve. Start with the simple things first. Let me know if I can answer anymore questions, thanks and have a great day.