The Hunter Mini-Clik Rain Sensor (Normally Open) is a simple yet incredibly effective tool for preventing your irrigation system from running during or immediately after a rainstorm. Designed specifically for battery-operated DC timers that require a normally open circuit, this sensor acts as an automated switch. When sufficient rain falls, it interrupts your timer's signal to the valves, saving water, reducing your utility bills, and preventing your landscape from becoming over-saturated and prone to disease.
Unlike electronic sensors that can be overly sensitive or prone to failure, the Mini-Clik relies on proven mechanical action. Inside the housing are hygroscopic disks that physically swell as they absorb rainwater, triggering the switch to pause your watering cycle. As the weather clears, the disks slowly dry and shrink, automatically resetting the system. With a fully adjustable rainfall threshold and an adjustable vent ring to control the drying rate, you can easily customize the sensor to perfectly match your local climate.
Detailed specifications for system planning.
| Specification | Details |
|---|---|
| Product Type | Mechanical Rain Sensor |
| Switch Type | Normally Open (NO) |
| Rainfall Settings | 1/8", 1/4", 1/2", and 3/4" |
| Mounting Options | Aluminum extension arm included (Eaves, fences, gutters) |
| Switch Rating | 24 VAC, 5 Amps |
| Sensing Mechanism | Hygroscopic Disks |
A quick guide to mounting, wiring, and adjusting your new weather sensor.
Step 1: Mount the Sensor
Using the included aluminum bracket, mount the sensor in a completely open location where it will receive unobstructed rainfall. Ensure it is not blocked by trees, roof overhangs, or within the spray path of your sprinklers.
Step 2: Set the Threshold
Look at the top of the sensor body. Twist the cap to align the pins with your desired rainfall threshold (1/8", 1/4", 1/2", or 3/4"). We recommend starting at 1/4" for most drip irrigation systems.
Step 3: Wire to Controller
Route the two wires from the sensor to your irrigation controller. Connect the wires to the designated sensor terminals on your battery timer. Polarity does not matter for this switch.
Step 4: Adjust the Vent Ring
Twist the vent ring at the base of the sensor body. Opening the vents completely allows the disks to dry out faster, resuming irrigation sooner. Closing the vents keeps the disks wet longer, delaying the reset in humid climates.
During unpredictable spring showers, how does the Hunter Mini-Clik Rain Sensor prevent overwatering?
During spring showers, the hygroscopic disks in the Hunter Mini-Clik Rain Sensor quickly absorb water and swell. Once the set rainfall threshold is reached, the sensor instantly commands your controller to pause irrigation.
Once the spring storm passes and the sun comes out, the vents allow the disks to dry and shrink at a rate similar to your soil, automatically turning your watering schedule back on without any manual intervention.
Can I use the Normally Open Hunter Mini-Clik with a standard AC wall timer?
No, you cannot. The vast majority of standard plug-in AC controllers require a Normally Closed (NC) rain sensor. This specific Hunter Mini-Clik model is Normally Open (NO).
This NO version is engineered for specific battery-operated DC node timers and specialized controllers that expect an open circuit to be closed by the rain event. Always check your timer's manual before purchasing.
How do I adjust the rainfall threshold on the Hunter Mini-Clik Rain Sensor?
To adjust the threshold on the Hunter Mini-Clik Rain Sensor, simply twist the top cap to align the stationary pins with the marked slots for 1/8", 1/4", 1/2", or 3/4" of rain.
Setting it to 1/8" will make the sensor highly sensitive, shutting down the system at the first sign of a drizzle. Setting it to 3/4" will allow the system to run unless there is a heavy downpour.
How long does it take for the Hunter Mini-Clik to dry out and reset the watering cycle?
The dry-out time for the Hunter Mini-Clik depends heavily on sunlight, wind, and humidity. However, you can manually speed up or slow down this process by adjusting the side vent ring.
If your soil is sandy and dries out quickly, open the vent ring fully so the sensor resets faster. If you have heavy clay soil that retains water, close the vents partially so the sensor delays watering for a few days.
Please verify your irrigation controller's requirements before purchasing:
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