How to Choose an Irrigation Controller

Sprinkler System Guide

Irrigation controllers are essential components of a Irrigation Sprinkler System.When DIY sprinkler system, the following article can help you better understand how to choose, install and replace a controller / timer.

What is an Irrigation Controller?

Hunter Pro-C Timer

Hunter Pro-C Timer

Irrigation controllers, also known as irrigation timers or lawn sprinkler system timers, are the nerve centers or brains of the sprinkler system. Sprinkler system timers send electric signals to the irrigation valves. The valves regulate the flow of water to the sprinkler system.

Irrigation Sprinkler System timers are the devices that allow you to set a watering schedule to meet your needs. You can set the days you want to water, the time of day you want the sprinklers to come on, and how long you want them to apply water.

Sprinkler system controllers may be mechanical, partly automatic, or fully automatic. Although irrigation sprinkler system timers are largely maintenance-free, the home or property owner might wish to upgrade and replace irrigation controllers or install irrigation controller parts or extra features. Sprinkler timer installation or replacement is very straightforward and easy and can be done by either the homeowner or by an irrigation professional.

How to Choose an Irrigation Controller / Timer

The only important decisions you need to make when selecting a controller / timer are as follows:

  1. Controller mounting location: indoor or outdoor
  2. Number of stations or zones – must be at least as many zones or areas your sprinkler system is broken up into.
  3. Number of programs (1, 2, 3, or 4) – should have at least 2 or more programs to give you the watering flexibility you want or need. The programs on a controller are very different from the number of stations on a controller. This is explained below.

IMPORTANT: The rest of the features you can choose from on a controller are just for added benefits or increased flexibility.

Indoor vs. Outdoor models
Sprinkler system controllers come in a wide range of makes and models. Choose lawn sprinkler system timers depending on the size of the sprinkler system and the user’s needs. Lawn sprinkler system timers come in two different types: indoor models and outdoor models. Indoor sprinkler system timers need to be sheltered from weather, and can be conveniently plugged directly into a 110-volt outlet. This is because they come with an external transformer as part of the plug-in cord that converts the 110-volts to 18 volts. Typical locations for mounting indoor timers are in the garage, building, covered patio, shed, pump house, closet, etc. Outdoor lawn sprinkler system timers are convenient, weather resistant, durable, and typically need to be hard wired for power instead of plugged into a 110-volt outlet. This is because the transformer is located inside the protective weather resistant cabinet and it is assumed that the electrical connection will need to be weather resistant also.

Outdoor controllers can be used as indoor controllers just by adding a pig tail (3 prong plug and power cord) to the power wires of the timer. People do this all the time to be able to get all the benefits of an outdoor timer with a weather resistant cabinet and typically all kinds of added features. An example of this is the Hunter ICC model controller which is one of Hunter’s best controllers. It has so many nice features that people will just add a pig-tail and make it an indoor timer.

Controller Stations
Typically, residential systems use irrigation controllers with 2 to 9 stations, while systems for commercial or public properties can have 32 – 48 stations or more. Each station regulates one zone or area of the lawn sprinkler system. When selecting irrigation controllers, know how many stations the system needs. Choose a sprinkler timer with extra stations, in case of later expansion.

Controller Programs
The number of programs a controller or timer typically has can range from 1 up to as many as 4. They are usually labeled as Program A, B, C, and D. Some controllers only have 1 program while most have at least 2 or more. A program is a set of watering instructions for stations that will run on the same days. When you set up Program A on the controller, you are setting the days you want to water, the time of day you want to start watering, and how long you want to water. If you have a controller with two programs, the lawn areas can be set up to be watered every day on one program and the flowerbeds and shrubs every other day on the second program. When a controller starts a program, it will go through the entire program before stopping or repeating the program.

Types of Controllers – Mechanical or Solid-State (Digital)

Some irrigation controllers are fully digital, including easy touch screen features. Digital sprinkler system controllers with basic features are suited to a more conservative budget. Other lawn sprinkler system controllers have an array of features and options for convenience and ease of operation.

Mechanical sprinkler system timers use manually-operated sliders and switches for programming. An electromechanical controller uses both an electric clock and mechanical switching. That is to say, they are made of a motor, wheels, dials, gears, and pins. These controllers are typically, easy to understand how to operate and program, and are less susceptible to power spikes and surges, but are much more limited in features than solid-state digital irrigation controllers.

Solid-State controllers have digital readout screen, have no moving parts, and use integrated circuits for the clock, memory and control features. These controllers are adaptable, offering many more features at a reasonable cost. More advanced Solid-State controllers such as Smart Controllers can adjust the watering schedule automatically throughout the year. Still other controllers operate solely on battery power, for areas with limited or no electricity. Solar-powered controllers are also available.

Features Available on a Controller

Some controllers come fully loaded with features for efficiency and convenience of operation. In others, extra features may be optional. Key features available on a controller can include:

  • Clock and calendar settings
    The user can program watering times, control watering cycles, and make seasonal adjustments.
  • Manual start and manual station operation
    The user can operate the stations or start the automatic cycle without affecting the programmed start time. This is helpful when you need to do some maintenance to your system. This feature makes it easier to check for leaks, misaligned or broken sprinkler heads and even perform basic tune-ups steps such as adjust spray patters and replace nozzles.
  • Master Switch
    The master switch overrides the automatic functions of the stations.
  • Master Valve Control
    The master valve prevents flow to the system, in case of water problems or system failure.
  • Station Omission
    The user chooses which stations operate, and which do not.
  • Pump Start Lead
    This turns on a pump start relay whenever a station activates, to combine irrigation and pump control. A Pump Start Relay is an electronic device that uses a signal current from the irrigation controller to activate a pump to provide water to the irrigation system. Never connect the controller directly to a pump as damage to the controller will result.
  • Rain Sensor
    A rain sensor shuts down the irrigation system if it detects rain. The purpose of a rain sensor is to stop watering when precipitation is sufficient. Most controllers allow for a sensor to be connected directly to the controller and allow you to easily override the sensor by using a Rain Sensor Bypass switch on the controller.
  • Battery backup
    The controller reverts to battery power in case of power interruption or outage.The battery typically will just allow the timer to maintain the time, date, and watering schedule. On some controllers it allows the user to program the controller without AC power. IMPORTANT: watering will not occur without AC power. The battery only keeps the time, date, and watering schedule in memory until the AC power is restored or the battery dies.
  • Non-Volatile Memory
    The controller retains its program data without a battery, even if the power fails.  The non-volatile memory allows the timer to maintain the time, date, and watering schedule indefinitely. IMPORTANT: watering will not occur without AC power.
  • Delay
    The delay feature allows time for valves to close fully in one zone, before opening the valves in another zone.

Where to Buy a Controller / Timer

For more information about irrigation controllers, options and features, or to purchase a new irrigation controller or sprinkler timer, go to
If you need more irrigation help, questions about irrigation system repair, or how to install a spinkler system, please visit

5 comments on “How to Choose an Irrigation Controller

  1. Hmm is anyone else experiencing problems with the pictures on this blog loading? I’m trying to determine if its a problem on my end or if it’s the blog. Any feedback would be greatly appreciated.

    • Is it just on this page, or are you having trouble viewing pictures on every page of the blog? I am not having any problems, so it’s probably on your end. If you have a firewall, it might be preventing you from seeing images. You can also check your browser settings to see if you have it set to block images from this site. If anyone else is having problems viewing the images, please let us know.

  2. I live in a Master Community, where the landscaping company controls the front yard watering. I would like to be able to also control the front yard watering, in parallel to the landscaping company. Is there such a controller available?? I know it would have to have some type of Diode system to prevent back feeding the current.

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