The Melnor Hydrologic Soil Moisture Sensor Model 15339 is a soil moisture and rain sensor. The sensor will interrupt the hydrologic timers by stopping them when it rains or it will delay watering when the soil is moist enough. It will be a great addition to your Melnor Hydrologic Water Timer(s) because it automates the delay watering feature that comes with the timers.


Melnor Hydrologic Soil Moisture Sensor – 15339 Review

The Melnor Hydrologic Soil Moisture Sensor works adds automation to your watering. When it is installed you will no longer have to set delay watering manually.
melnor automatic rain delayThe water timer will communicate automatically with the rain moisture sensor. You just need to be careful where you bury the rain/moisture sensor so that you may not interrupt watering unnecessarily. See the commonly asked questions below.

Melnor has 2 types of soil moisture sensors. The 3300 AquaSentry® Soil Moisture Sensor and the 15339 HydroLogic® Soil Moisture Sensor. The latter, Melnor 15339 Hydrologic Moisture Sensor, will work with models 53015, 53100, 53280 Hydrologic Water Timers only.

With the sensor installed you do not have to manually adjust the watering schedule to skip a cycle if it is raining, the sensor will monitor the soil water content and automatically delay watering depending on the circumstances. If the soil is moist enough, it will not water. If it is raining it will not water. This is a huge saving both on your time and water bill! Also see Melnor Rain Cloud Review.

A Quick Look At Melnor Hydrologic Rain Sensor – 15339 Features

In summary below is a list of features of this sensor at a glance. You will notice that owning and installing it will alleviate the hassle of monitoring your watering schedule.

  • Works with Melnor HydroLogic Advanced Water Timers
  • Stops watering when it rains or is not needed
  • Saves water bill
  • Promotes water conservation
  • Prevents over-watering
  • Comes with 16-ft. long cord
  • Limited 7-Year Warranty

It is important to note that this sensor is compatible with the Melnor Hydrologic Water Timers only. Melnor has another series of water timers, the Aquatimers. The Aquatimer digital water timer series are discussed in more details here – Melnor AquaTimer Water Timers

When you purchase the Melnor AquaSentry Automatic Rain Delay Water Timer to install it in your yard you might have a few questions to know how it works, since it does not come with instructions or manual. You might want to how to set it up, how deep to bury it, how to connect it to the water timers, etc. We will attempt to answer a few of the common questions to help you make the most of your sensor.

Commonly Asked Questions About Melnor Hydrologic Soil Moisture Sensor

Though being a big brand Melnor does not seem to have a 15339 manual such that you might have to contact their customer service for assistance. You can either call or email them!

How To Connect It To The Water Timer And Set It Up?

Connecting the sensor to the is as easy as plugging it in with the 16ft cord it comes with. What is important to note, however, is that where you bury the sensor, it must the last zone to be watered. It must also be not in the water or sprinkler path. Bury it such that the sipping water will gravitate to it, otherwise, the watering might stop in the process before completion. This will be because the sensor will sense that the soil is moist enough and react.

How Many Zones Does The Sensor Control?

The sensor does not control zones, it controls the water timer and the water controls the zones. The Sensor plugs into one water timer and by default, it will affect all the zones controlled by the water timer. The sensor will not be specific to one zone and does not control zones.

What Does The Flickering On The Sensor Mean?

When the sensor is has a flickering light it means it is interrupting any watering schedule because there is enough moisture in the soil. How sensitive the sensor is to the moisture in the soil is controlled by the control knob on the device. The knob can be turned to 1, 3 or more drops.

The less drops the knob is turned to the more sensitive it would be to soil moisture. If the light is flickering but you feel the soil is not wet enough, you may adjust the knob to a higher drops that way it will trigger the watering once the scheduling allows for watering.

Where Does The Sensor Plug-In?

The sensor plugs into the back of the hydrologic water timer. The water timer has a small plug at the back plugged with a black rubber button. Plug the long cord that comes with the sensor in this plug hole.

Melnor Hydrologic 53015 Advanced Aqua Timer Review Video

The following video will help you answer some of the questions you might have about this sensor.

Where To Buy Melnor Soil Moisture Sensor-15339

This Soil Moisture Sensor, by Melnor Inc, is available online from several reputed merchants like Home Depot, Lowe’s, Amazon. However, the place to shop for this product is at Amazon because you can learn even more about it. Users leave feedback and ask questions like in an online forum community. They leave informative reviews to help you make an informed decision before you can order a product.

If you want to find information on any item, equipment, tools, accessories, supplies, hardware products or service should be the first place to visit!

Melnor – HydroLogic Soil Moisture Sensor Price

The price on this item makes it not qualify for free shipping at but you can bundle it with an additional 4 zone hydrologic water timer Melnor 53280. You can expand a 4 zone (or 2 zone) to cover even more zones by purchasing an additional one. This is ideal when you have many areas to water. You might have a vegetable garden that you water with a water hose, lawn that you water with sprinklers and other zones that have different irrigation needs and increasing the timers to control water in more areas would be wiser.

Other Moisture Sensor By Melnor

There is Melnor AquaSentry Automatic Rain Delay Water Timer model 3300 and is compatible with the Melnor Aquatimer water timers models 3015, 3060, 3100, and 3280.

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