WATER DOES NOT TURN OFF
When a part of the system stays on well after it was scheduled to shut down, you know there is a problem. Sometimes the problem is an improperly set irrigation controller. In other instances, there is a mechanical failure with a control valve and the system will need to be turned off at the main water source.
TURNING OFF YOUR CONTROLLER
Every type of controller, mechanical or digital, will have some type of OFF position. Some makes of controllers label the OFF position as RAIN OFF or simply RAIN. If turning off the controller fails to shut the system down, you must go next to the main water source for the irrigation system.
TURNING OFF THE SYSTEM AT THE WATER SOURCE
Every sprinkler system, if properly installed according to local codes, should have a separate cut off for the irrigation system. There are generally three basic types of cut off boxes depending on the age of your irrigation system.
Mid 1968 and older should have an oval or round metal or galvanized cover.
1968-1980's may be in a large rectangular concrete box with a small metal trap door in the center of the concrete top.
1980's-current will probably be in a large green or black plastic box.
Once you locate the box, you should be able to open the lid with a medium sized screwdriver. Each backflow device installed after 1968 should have at least two cut off handles, they may be a lever type handle or gate valve type handles (something like large faucet handles). Don't be surprised if you find the handles either broken or partially broken, they are notorious for twisting off due to corrosion. If the handles are gone, you may still be able turn off the water with a pair of channel locks or vice grips. Once the crises is solved, you should call a professional repair technician to locate and repair the problem.
If you have a wet spot in your lawn, first turn on your sprinkler system to see if you can spot any obvious problems. Next, be sure your controller has not malfunctioned and that you are not over watering. Turn your sprinkler system off at the control panel for a couple of days to see in this corrects the problem. If the problem persists, turn off the water at the main water supply. If the leak is in your lawn sprinkler system, the area should dry within a couple of days.
When your electronic or digital controller does not operate properly and/or will not accept a program you should try to clear the display. Remove the back up battery and unplug the controller from the wall. After approximately 15 seconds, re-power the controller and see if this solved your problem. Sometimes these controllers are affected by a power surge that causes the memory to scramble and you simply need to clear the memory. If this fails to solve your problem, you may need to call an irrigation technician.
Equipment
Controllers automatically operate your lawn sprinkler system. There are two basic types of controllers, mechanical and electronic or digital. Both types do basically the same job, but each offer different types of features.
Mechanical controllers were the only type of controller available until the late '70's. Operated by electric motors and gears, they are very reliable since their basic design is generally uncomplicated. They are unlikely to be affected by power outage and power surges because they are mechanically programmed.
Mechanical controllers however, have limited programming choices. Most mechanical controllers do not have the ability for any type of independent watering schedule so the watering options for your sprinkler system are limited. For the individual who is technically challenged however, they are a great choice because they are easy to set and operate.
Digital/computer controllers have the ability to set several types of program options for each day and for each section of your lawn sprinkler system. There are many types of these controllers available with different degrees of complexities.
When choosing your digital controller, be sure you purchase a brand that you feel competent to set. Check with your friends and neighbors to find out what type they use and the degree of difficulty in daily operation. Do not rely solely on the manufacturer advertisement that is "easy to program".
A valve is a device that turns the water on and off to each area of your lawn. You will generally have several valves in your sprinkler system, depending on the age of your system and the size of your yard. There are three basic types of valves available. Manual valves, electric valves and hydraulic valves.
Manual valves require the homeowner to manually go to the valve location, generally near the front or rear entry to the property, use a special valve key to manually turn on each valve individually for each section of the lawn. Many of the sprinkler system's installed prior to 1960 were installed using manual valves.
Electric valves are what most installers use today. They operate using 24V current from the controller to the valve. Wires run from each valve to the controller and are generally installed with the main line pipe below ground. When the controller sends current to the zone valve, it magnetically opens the solenoid and allows the valve to open.
Hydraulic valves are the least common type of valve installed. It would be unlikely for a company to offer these types of valves on a newly installed sprinkler system but some of the older systems were installed using hydraulic valves. Hydraulic valves operate using water pressure to turn the valve off or on in lieu of electricity. There are small tubes that connect from the controller (if applicable) to the valves. When the controller is activated, a small amount of water is released though the tubes and allow the valve to open. Most homeowners who find themselves the proud owner of a hydraulic system find it difficult to locate qualified repair technicians.
Spray heads are the type of heads that pop up and spray. Spray heads are installed in the lawn area and are designed to pop up while watering and retract to ground level after the watering cycle. Spray heads come in a variety of sizes, from 2" pop up to 12" pop up, with the 4" pop up being the most common. 
Shrub areas can be watered using either the taller 6" or 12" pop up heads but are more commonly watered using stationary fixed heads. Shrub risers are usually copper pipe or PVC risers. Two types of spray nozzles are available for the shrub areas; spray type nozzles, the same type used on pop up lawn heads or special shrub nozzles that have a smaller mist type spray for delicate plants.
Rotary heads are the type of heads that typically have 25' or more radiuses. They come in two basic types of design, gear driven or impact. Rotary heads are best used when the area is open and free of things that could potentially obstruct the water.
The State of Texas requires every lawn sprinkler system installed in the State of Texas to be protected by a certified backflow prevention device. These devices are required to protect the quality and safety of the drinking water supply. They prevent the sprinkler water from backing up into the house water.
