What to do if the dial breaks off

If the dial breaks off or gets very difficult to turn, you have some options.

  1. You can send it to us for repair.  We’ll also give it a good tune up and replace any other internal components that sometime fail, that way you’ll not only get another dial, but also know the rest of your timer should keep working well for a long time.  (Our oldest timer that we’ve repaired and put back in service was dated 1991, so they have a lot of life in them).
  2. Do it yourself options:  You can contact Irritrol directly and ask them to send you a replacement plastic dial; they usually do.   They’re not too difficult to replace on your own.  Look at the irritrol.com website for their phone number.



How to replace the transformer

Transformers rarely fail, and when they do, it’s usually caused by people not turning the power off when they are moving wires and the 24VAC wires touch.  Sometimes a failed solenoid could cause transformer problems but the timer usually shuts off and issues a FUS message before the transformer is damaged.  Some models also have fuses on the back terminal board that helps protect it.

A note of caution – the transformer is connected to your household 110/120VAC power, which is dangerous.  Be sure to take precautions by turning off the power before working on the unit.  You should not attempt it unless you are experienced enough to do so.  This post does not contain sufficient information to work with these voltages safely; If in doubt, contact someone who is qualified. 

Most of the time people think that the transformer is bad when it isn’t,  Follow the DIY page topic on ‘How to test if the transformer is good’ to know for sure.

Testing the transformer with a resistance meter

As one optional and additional check before you tear it apart, you can use a multimeter to perform some simple transformer checks.

Turn off the power and disconnect the AC power connection at the bottom of the transformer case on the right-hand side.  There should be black, white, and green wires. Remove the timer ribbon cable from the back terminal board.  Your multimeter’s resistance measurement settings should be set to the lowest resistance range. e.g., 0-50ohms…

  • Measure the resistance between the transformer output wires, the thick red and yellow wires connected to the 24VAC terminals.  It should measure around 1.5-2.5 ohms.
  • Measure the input side of the transformer between the black and white wires.   This should measure around 20-24ohms.

If either one measures open, you know the transformer is bad and must be replaced.

Removing the Transformer

If you conclude that the transformer is bad, you can use the following information to help you understand how to replace it. I generally start on the left side and work my way around counter-clockwise.  REMOVE THE KEY FIRST, or it can be difficult to remove later.

After removing the case, you’ll see how the transformer is connected into the case.  You can often find them on ebay or at a local landscape supply store.It should be rated for 1.25A, 24VAC.



The transformer typically looks like this.

If this info has helped you, please consider making a donation – we depend on you to keep this information available.

Note, some newer transformers have an additional green wire coming out the bottom (reference the photo above).  Keep reading for more information about it.

2020 Update on the green wire or ground wire found on newer transformers:

Background Material for understanding grounding, green wire ground, surge protection:
Irritrol has had surge protection circuitry on their newer back terminal boards for a long time. It’s provided by those “blue” capacitor looking components that are actually MOV or TVS devices. They do not not work unless they have a ground path for surge current follow. Irritrol’s previous transformers never brought the ground wire out into the compartment where the back terminal board is for you to easily access it. It was assumed that the ‘user/installer’ would run a separate ground wire to the back terminal board for this purpose. Unfortunately, there was no way to route the ground wire from the ac mains to the compartment without drilling some holes and adding your own wire. Alternately, and preferably, the user was expected to bring in a separate ground wire through the portal with the valve wires and tie it to a grounding rod. Adding your own grounding was a hassle and expense and basically no one ever did it. I’d estimate that 99% of customers never had a ground wire hooked up at all, causing the surge protection circuity to be useless.

To fix this, (20+ years later) Irritrol started manufacturing transformers with the AC ground wire passed through from the AC Mains side through to the main compartment. There are now 3 wires; red, yellow, and green (or maybe green/yellow-stripe). Although not as good as having your own grounding rod, this is much better than nothing and now that it is “conveniently accessible”, people will or at least should use it.

Now to answer your question.
If you have a newer transformer with a green wire that wasn’t there before, connect it as follows:
1) If your terminal board has a GND or Earth Ground screw terminal, connect the wire to this terminal.
2) If you don’t have that terminal, but have a smaller, unlabeled screw terminal located below the 24VAC terminals, connect it to this terminal.
3) If you don’t have either of the above terminals on your back terminal board, simply connect the green wire ground in the VC terminal
with any other VC wires. (Usually these wires, by convention, are white, but they don’t have to be)
4) Of course, if you have your own grounding system (rod, etc.) already in place, use it instead and just cap the green wire off with tape or a wire nut so it doesn’t touch anything else.

Note that it does not matter what order you put the red and yellow wires on the 24VAC terminals; either way is fine, but “R”ed on the “R”ight is a common convention.

If this has been helpful, please consider making a donation on my site; I don’t get paid by Irritrol or any company for the service and the proceeds go towards kids education and to keep this site going.

Good luck,

Brian, Jen, Meghan and Ben – the rainDialDoctors

What to do if the outer case door breaks off?

Irritrol RainDial Interior/Exterior Case Configurations

The Rain Dial series of controllers come in two main configurations – interior and exterior.   The exterior models have fairly solid housing and hinge mechanism.  They also have the transformer contained on the rectangular section to the right.
The interior irritrol raindial models contain an separate transformer that plugs into an AC outlet.   The hinge on the case is just a thin layer of plastic that can eventually wear down and break off.

What do do when the Case Door breaks off

Here are my thoughts on what to do with a broken hinge:
Unfortunately, there are note any good “official” solutions that I’m aware of. However, several customers have reported reasonable success with the following options:
  1. Use the extra thick black “Gorilla” duct tape; it’s very durable and has a good adhesive, better than typical duct tape.  They sell this at lots of stores including Home Depot and Lowes. 
  2. Use the packing tape that has the nylon strings built into it
  3. You might be able to add your own metal hinge to it, but that a bit more work; they sell small hinges in most hardware stores.
  4. Check with a local landscaper – sometimes they purchase the interior models because they’re cheaper and then take the controller module out of them to put in an exterior case (they’re actually the same, it’s the transformer that is rated external or internal).   Thus, they often throw out the interior case…

If anyone has other solutions, please comment below.

(c) copyright 2017 Brian Keller – aka the RainDialDoctor

How do I program the RD600

For help programming the RainDial RD600-1200 series sprinkler/irrigation controllers, see the following programming guide and then review the manuals above. This is a quick guide, not the user manual.  If you’d like to see the full manual, click here.

Irritrol Programming Templates and Tips

Ask your questions here – (They will appear shortly)

To avoid spam and other problems, your comment won’t appear until it’s been approved.  Don’t worry if you don’t see it right away.

To add a question, go to the bottom of the page, fill in the comment and click Post Comment.  

Please look at the DIY Troubleshooting section before posting; answers to most questions can be found there. 

You can also reply to other people’s questions if you like. (Thanks for helping)

Please try to include the following with your question, list:
1) the date code (located under the battery),
2) the model number shown on the face of the controller (usually below and to the left of the dial, e.g., RD-600 or RD-600-R).
3) Color (mostly Gray or Blue) based on the example rainDials shown at the top of the page.