How do you clear the FUS or FU5 message?

(All information here is copyrighted by Brian Keller, 2012).

If this troubleshooting information doesn’t help solve the issue and you’d like to have it repaired, please send it to us.  We repair all models of RainDial timers.

The Irritrol RD-600 series sprinkler controller message ‘FUS’ stands for Fuse.  If you see a 5 (FU5), the 5 represents an S.

This page explains:

  1. What the FUS message really means
  2. How to clear the message
  3. How to determine what is causing the FUS message.
  4. How to fix the FUS message

1. Bottom Line First: This is important to know about the RD600 irrigation timers

  • Despite the RD600 message saying FUS, this does not mean the fuse is bad as one would expect.
  • The FUS message is almost always caused by a shorted solenoid or wiring, not a fuse…).  Solenoids are the cylindrical electrical ‘switch’ that are screwed on the top of the valve; they have two wires going to it. They are fairly easy to replace.
  • although it is not related to the fuse message, you can read about checking the fuse here.
  • In rare cases with the -R series, a full reset resolves the problem.  All the information you need to know is below.

2. To clear the FUS message:

  • Set the dial to the Current Time position
  • Press the + or – button
    • If the FUS error won’t clear, perform steps to do a factory reset
      (try both old and newer timer reset sequences)
  • If the FUS error clears, but keeps coming back, the following information will help figure out what valve is causing the problem and how to fix it:

What valve is causing the FUS message?

  1. If the fuse is good and the message comes back
    1. the suspected “problem valve” number will be displayed on the top of the LCD screen with the FUS message.
    2. Try removing the wire on the terminal board for that valve number, clear the message and run the schedule again.
      1. If you have multiple numbers appearing, remove the wire for each of them, including the MC/Pump wire if you have one.  Clear the message, and run the schedule without the valves connected.
    3. Reconnect the valve wires one by one until you find out which one causes the error to re-appear; this is your suspected bad solenoid.
    4. If you think you have a bad solenoid, you can go to this page for more information: Testing and Replacing Valve Solenoids
    5. If the RD600 series FUS message returns with the same valve number even if you moved the valve to a new location, it’s unlikely that you’d have two solenoids fail at the same time so check the wiring for damage due to recent digging by people or pets, etc…
    6. If the RainDial timer shows the FUS message with all valve numbers that you are using, it’s likely a problem with whatever is connected to the Pump/Master-valve (MV) screw terminal.  This is because the pump is activated for all valves, so if it is failing, every valve will detect an over-current condition and active the FUS error.  All RD-600 series timers have a MV/Pump terminal on the back terminal board.   You can try clearing the FUS message and then remove the wire to this terminal.  Then run the timer to see if the FUS message still appears.  Of course the water won’t flow very much because the pump is off, but if no FUS message occurs, you know that whatever is connected to the MV/Pump terminal is likely causing the problem. You can disconnect the wire to that terminal and measure the resistance between the wire (not the terminal) and the VC terminal. A typical valve solenoid is 27ohms of DC resistance or more.  If you measure significantly less, it’s likely bad.   Check the specification on your pump/master-valve relay to determine if the resistance is too low or not, or try replacing it.
    7. You can test if the solenoids are bad if you have a meter capable of measuring resistance.  Simply turn off all the valves and measure between the VC/Vcom terminal and the valve/station terminal (e.g., between VC and 1)  every valve including the MC to VC/Vcom should measure around 20 to 40 ohms.   If infinite ohms, you have a broken wire or bad solenoid that results in an open circuit and looks like it’s missing. If you have lower resistance, it’s likely that the solenoid has started to short out and is failing, or your wires are crossed and touching somewhere.  See this post for more information on testing.
    8. If the message appears with no valves or MC/Pump wires connected, try doing a full factory reset (use both the older reset method and newer (-R series) reset methods.  If no luck, it’s still very unlikely to be problem with the controller but if you’re convinced it could be, contact us here.

Other troubleshooting ideas: If the valves are the same, you can swap solenoids with a known working valve and see if the problem follows the suspected bad solenoid.

You can also disconnect the bad solenoid and clear the message.  If you do this, the timer will work normally except for the one valve that was disconnected.

If we’ve helped solve the problem and deserve a little credit, please leave us a donation, we’d really appreciate it. 

For full RD600 series controller reset:
Older models can be reset by removing the battery and power from the controller – this may reset programming. Always try this method first, then the full factory default reset sequence.  All the details can be found in this DIY page:

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