Are Decoders Better?

May 25, 2021 | Agriculture, Commercial Landscapes, Domestic Gardens

Are decoder irrigation controllers better than conventionally wired irrigation controllers?

Yes – For the right project they are definitely better


Irrigation controllers have improved exponentially over the last few years. Smart irrigation controllers that give you remote access to your irrigation system are not “run of the mill” and are getting more and more affordable.

Irrigation 2 wire or “decoder” systems have become more mainstream recently. The decoder technology has been around for decades, But up until recent times this 2 wire technology was restricted to use on very large irrigation systems. Decoder systems could really only be found on golf courses, large sporting precincts and in large council/municipal parks and gardens. The technology was fantastic and even made sense financially on large systems. But when it came to small and medium size irrigation systems. There was no real cost savings to be made by choosing a decoder controller. As the hardware was very expensive, back then a decoder controller probably landed in the tens of thousands of dollars.

So what’s changed?

In recent times (lets say over the last 10 years) decoder irrigation systems have been released to the market that are well suited to medium sized irrigation systems. The systems that come to mind that suit smaller/medium sites are the

  • Hunter EZ decoder system – that connects with Hunter Hydrawise (cloud/phone app)
  • Weathermatic decoder system – that connects with Smartlink (cloud/phone app)
  • Rainbird ESP LXD  – That connects to Rainbird IQ3(Remote Desktop app)  or Rainbird IQ4(cloud)

*Note – Each of the above controllers have a conventionally wired variant

*There are other great systems that are available on the market that also may suit smaller sites, however I have omitted them from the list as I find they have a steep learning curve when learning how to use these systems. The systems I have included I find have very user friendly interfaces

*Each brand has slightly different manufacturer requirements, always follow manufacturer recommendations


When is it beneficial to use a decoder controller?

Due to the easy access to decoder equipment now for smaller projects we think you should consider using a decoder system in the following scenarios

·         When you have more than 18-30 zones on the irrigation system (It starts becoming cost effective at this point to look at a decoder system over a conventionally wired system)

·         When you may need very long wire runs on a long but skinny site (like on a streetscape/ new estate entrance)

·         When you are planning on adding to the irrigation system at a later date (You don’t have concerns about there being enough irrigation wire in the in the field like you do with conventionally wired systems)

·         When you need to manage multiple water sources and sensor equipment (*limited to some brands/models)

Some things to consider when using decoder equipment:

·         Earthing really matters when using decoder equipment – to protect your irrigation infrastructure, always follow manufacturer recommendations.

·         Getting wiring right is important, using correct jointing techniques for connections will ensure system longevity, Moisture in decoder equipment never ends well

·         Fault finding can be more difficult than conventional wired systems

·         Use the wire recommended by the manufacturer

·         Controllers also have a maximum capacity and the appropriate controller should be chosen to accommodate your irrigated area

·         Some solenoid valves on the market indicate that they are not suitable for use on a decoder system

·         Decoder systems can be affected by electrical interference


When to use a conventionally wired system:

I may choose to use a conventionally wired system if

·         All of the zones are located very close to the controller locations

·         On systems under 18 zones

·         You don’t want to use any earthing equipment (maybe you are in an area with lots of services and driving an earth rod into the ground is undesirable)

If you need any help with anything decoder related, please reach out!

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