Watering Index System
Quick Installation Guide
Revised February 1, 2010
Underhill International Corporation
20505 Crescent Bay Drive - Lake Forest CA 92630
The WaterDex™ System works by modifying your existing watering schedule
based on your regional need. This “watering index” is transmitted from the
Wireless Remote Control to the Receiver connected to your existing sprinkler
timer. For most effective use ensure that your timer is set to 100% if it has a
water budget or seasonal adjustment feature and that the times for each zone are
set for your highest use month – usually July or August.
If you need any assistance in determining an appropriate watering schedule,
please consult your local water authority.
1. Verify that all components are present: WaterDex™ Wireless Remote Control,
WaterDex™ Receiver, Batteries, and Accessory Bag.
2. In the next step, you will be disconnecting the power to your existing timer.
Prior to disconnecting the power and If your sprinkler timer has a battery
back-up which maintains the timer programs in the event of a power loss to
the timer, you may want to replace the battery to ensure that your timer
programs are not lost.
3. Disconnect power to the existing sprinkler controller.
4. Access the sprinkler valve wire connections on the controller terminal block.
5. Connect the two BLACK wires from the WaterDex™ Receiver to the controller
terminal block power connections (typically labeled 24 VAC). The wires may
be installed on the controller terminal block power connectors in any order.
6. Disconnect the sprinkler valve common wire(s) from the controller terminal
7. Connect one BLUE wire from the WaterDex™ Receiver to the common wire
connection (typically labeled “COMM”) on the controller terminal block.
8. Using the wire nut provided, connect the second BLUE wire from the
WaterDex™ Receiver with the sprinkler valve common wire(s) which were
disconnected from the controller in Step 5 above. Mount the WaterDex™
Receiver near the controller using the Velcro tape or attach to the wall using
the mounting screws and anchors provided.
9. Reconnect power to the controller and ensure that the POWER LED on the
WaterDex™ Receiver is lighted indicating that the WaterDex™ Receiver is now
Remove the four screws from the rear cover of the WaterDex™ Remote
Control and install the batteries provided. The LED on the dial will slowly flash
to indicate power.
The WaterDex™ system is shipped from the factory with the Remote Control
“paired” to the Receiver. When the Receiver mates with the Remote Control,
the Receiver LINK LED will glow steady.
Place the WaterDex™ Remote Control anywhere in your home within 150 feet of
the WaterDex™ Receiver. Ideally, the WaterDex™ Remote Control should be
placed where the WaterDex™ dial may be conveniently adjusted throughout the
year as required. Velcro strips and magnetic tape can be found in the accessory
bag to assist in mounting the WaterDex™ Remote Control. The Watering Index
Value for California may be found at:
For other regions please contact your local water authority.
Tips & Troubleshooting
Before installing the WaterDex™ system, verify that your sprinkler timer is
programmed for maximum seasonal watering – typically a late Summer watering
schedule. For assistance in determining an appropriate schedule, consult your
local water authority. In Southern California, an online resource from the
Metropolitan Water District can be found at:
Even if your controller has a “Seasonal” adjustment or “Water Budget” feature,
make sure this is set to 100% to effectively use the WaterDex™ and the weekly
Remember to set your controller to water in the early morning when the air is
cool and still. Avoid watering between the hours of 9:00 am and 5:00 pm when
much of your water will be lost to evaporation.
The LEDs of the WaterDex™ Remote Control and Receiver indicate the status
of the system.
If the WaterDex™ is not working, please check these first.
a. Slow Blink indicates sufficient battery power.
b. Rapid Blink indicates batteries need replacement.
c. No light indicates dead batteries.
a. The RED Power light steady indicates power connected.
b. The GREEN Link light steady indicates connection to Remote
As part of optimizing landscape water use, it is important to periodically turn on
each irrigation valve to see that the valve and each sprinkler served by that valve
are operating properly. Look for sprinklers that are not popping up properly,
shrubbery or grass that is interfering with the watering pattern of a sprinkler,
broken nozzles, clogged nozzles, sprinklers that do not pop up vertically,
sprinklers that are spraying sidewalks and driveways.
Because it may take several days for your landscape to exhibit visible effects
of adjustments to your WaterDex™, it is recommended that you do not make
adjustments of more than 10% in any week to your WaterDex™ Remote Control.
What if I normally turn off my sprinkler system during the winter months?
The Watering Index is value that is intended as a guide. If you know based on
experience that your yard does not require any watering at all in the Winter
months, then by all means, rely on your experience. In the Spring when you
normally begin your annual watering regimen,
WaterDex™ can hopefully help you determine how often and how large
increases in watering should be as we head toward summer, and how often and
how large decreases in watering should be as we again head toward Winter.
Remember to keep your WaterDex™ Remote Control in a convenient place to
set your weekly Watering Index.
Please consult your local water authority for any assistance regarding
landscape water use.