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Weathermatic SMARTLINE 4 Station Indoor/Outdoor Controller | SL1600

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Sale Price $117.58
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Weathermatic SL1600 4 Zone Base Controller

  • Weathermatic SMARTLINE Indoor/Outdoor Controller
  • 4 Station (4-zone base model controller expandable to 16 zones)
  • Modular Controller

Features & Benefits

  • 4-zone base model, expandable to 16 zones using SLM4 4-zone hot-swappable modules (Indoor/Outdoor rated)
  • Internal 120VAC/230VAC transformer with plug and play pre-installed 6' line cord (removable for conduit-wired installations)
  • Large backlit LCD display
  • 2 run modes: Standard mode runs user input zone run times; Auto Adjust mode requires SLW Series On-Site Weather Station to calculate weather based run times that override user input zone run times
  • Rain/Freeze sensor bypass/active button located on face panel displays sensor status with tri-color LEDs (red indicates sensor is prohibiting irrigation; orange indicates an extended rain delay after weather station rain sensor permits irrigation; green indicates normal operation)
  • 4 programs: A, B, C; program D can operate concurrently
  • 8 start times per program
  • Nonvolatile memory and real time clock/calendar circuit to retain programs as well as correct date and time - with no battery required
  • Zone run times settable from 1 min. to 9 hrs. 55 min. with operation countdown displayed in hours, minutes, and seconds (zone run times overridden by weather based calculated values in Auto Adjust mode)
  • Watering day selections of custom days of the week, odd/even, or interval days
  • Omit settings: omit time of day window, omit day(s) of week, and omit up to 7 calendar dates
  • Seasonal % adjust by program, by month for simple year round water budgeting (monthly percentages overridden in Auto Adjust mode)

Product Details

  • Input: 120 VAC/60Hz @ 400m for 3 valves
  • Output: 28 VAC, 1.0A maximum
  • Fuse: 1.0A, slow blow
  • Dimensions: 9-1/8" W x 10-1/2" H x 4" D (23,2 cm x 25,7 cm x 10,2 cm)

Auto Adjust Features

  • ZIP Code input (5 digit) or Latitude input (+/-60 degrees from EQUATOR) establish location of site for solar radiation calculation
  • Sprinkler type input allows selection for zone sprinkler type (SPRAY, ROTOR, DRIP, BUBBLER) with preset precipitation rate or specific input of the zone precipitation rate (.2 - 3.0" per hour)
  • Plant type input allows selection for zone plant type (COOL TURF, WARM TURF, SHRUBS, ANNUALS, TREES, NATIVE) with preset crop factors or specific input of the zone crop factor (10 - 300%)
  • Soil type input allows selection for the soil type (CLAY, SAND, LOAM) and slope (0 - 25 degrees) for the purpose of automatically calculating a run/soak period to virtually eliminate run off
  • More/Less is settable by zone (-50% to +25%) for the purpose of fine tuning Auto Adjust run times to accommodate factors like shade, wind, and sprinkler inefficiencies

Advanced Functions

  • Fault review displays all faults, including open and shorted zones
  • Diagnostic test function using on-board multi-meter displays transformer voltage; milliamp measurement for each zone
  • Built-in valve locator function for locating hidden valves by simply listening for the audible chatter of the solenoid created by a unique electrical frequency (patent pending)
  • Review menu displays accumulated ET deficits by zone (in inches) and corresponding zone run times for the next available watering day
  • Review menu displays maximum run time and minimum soak time used during Auto Adjust mode
  • Review menu displays temperature readings (daily high/low) for previous 5 days
  • Review menu accumulates total run times by zone from the last reset date
  • Rain delay of 1 - 7 days may be selected (to pause and automatically resume operation)
  • SLW Weather Station extended rain delay programmable from 0 - 99 hours
  • Run/Soak cycles allow setting of maximum run time and minimum soak time by program for use in Standard mode only
  • Zone-to-zone delay programmable for 1 min. - 3 hrs. to accommodate slow closing valves and recharging of water supply
  • Master valve timing sequence with zone-valve programmable by "On Delay" (1 sec. - 1 min.; 2 sec. default) and "Off Delay" (1 sec. - 3 min.; 5 sec. default) to allow for line fill and slow-closing valves
  • Master valve/pump start operation assignable On/Off by zone
  • Clear program function to selectively delete an individual program
  • Clear all function to delete all programs

Irrigate From Anywhere, Upgrade with SmartLink*

Imagine having immediate access to every element of your irrigation system from inspections, to repairs and water usage. With the SmartLink Cloud-based Landscape Network, you and your landscape professional will have unprecedented control and visibility over your entire system. Now your landscape professionals are capable of making a simple programming change, monitoring the health of the system, or even being alerted if a problem occurs. They can instantly shut down your system in an emergency and help you comply immediately with local watering restrictions, avoiding costly fines.

*Note: Wifi features require the SmartLink (Sold Separately) Images not to scale.

Build Your SmartLink Network*

You can now expand your SmartLine controller to maximize water savings, improve efficiency and improve landscape beauty. After ensuring you have the modules to accommodate all your zones, add an on-site Weather Sensor that takes into account rain and freeze, but also adjusts for temperature and other conditions that impact the need for supplemental watering. Adding the SmartLink aircard gives you reliable cellular connectivity and access to the SmartLink web application so you can program your controller and manage it from from your computer, tablet or smartphone. This capability also includes water use reporting so you get real-time visibility to the dramatic water savings from Smart irrigation and email alerts for indications of any issues that will impact water savings and landscape beauty.

*Note: Accessories Sold Separately Weathermatic SMARTLINE 4 Station Indoor/Outdoor Controller

Related Articles & Videos



Product Tag:
Top of the Line
Product Type:
Controller (AC)
Enclosure Type:
Max Station Run Time (HRS):
Light Commercial, Residential
Enclosure Type:
SmartLine 1600
Freeze Sensor Compatible:
Power Source:
AC Powered
Number of Programs:
Start Times Per Program:
Sensor Compatible:
Rain, Freeze
Rain Sensor Compatible:
Controller (AC)
Residential and Light Commercial
Enclosure Type:
4.3 / 5.0
15 Reviews
5 Stars
4 Stars
3 Stars
2 Stars
1 Star
Weathermatic SL1600 Controller - Love It
This Weathermatic SL1600 Controller is the only controller I have found that has all the features it has. I was amazed to be able to avoid calling a repair company when my sprinkler system was having problems because this controller was able to locate my lost valves for me and then send test signals to actually tell me what was wrong with the valve. It told me the valve solenoid had a short in it. So I was able to replace the solenoid and fix the problem. But what was really cool was the controller just skipped that valve during the watering cycle until I had time to get the parts delivered and fix the valve. There is NO OTHER Controller out there like this one! Love it!
May 29, 2014
Reasonably priced, full-featured timer
I bought this to replace a failing Hunter timer that was probably 20+ years old. It only took me about 45 minutes to mount it to the wall and wire up my six watering zones. The only problem I encountered was that the connection for the common wire is a few inches past the terminals for the zones, so I had to use a piece of wire and a wire nut to make an extension. I'm not using half the features that are available, but it's nice to know I can upgrade to a weather station and make it more automated if I choose.
June 9, 2014
over 6 years ago
Weathermatic SL 1600
The SL 1600 is a great controller and has so many benefits, especially if you use for a job where you need to know if someone modifies the zone time or makes any changes to the program, as the controller e-mails me an alert.
September 16, 2018
over 2 years ago
Great timer!
the built in diagnostics allow you to check the circuit to the solenoid on the timer. Great time saver when problems arise.
July 28, 2014
Great controller
Have used this unit for many years on my personal home, and served as a rep for this line for years as well. Great controller, great brand, stand behind it.
February 4, 2020
Weathermatic SL1600
I've used Weathermatic products for years to irrigate my lawn and flower beds. I've found them to be very easy to use and dependable. A great product at a good price.
March 17, 2016
Impressed with the many features
I am satisfied with the product. It has helpful features that are aplicable to my yard.
July 3, 2018
over 2 years ago
Handel's everything we need.
We may have an unusual application for our timer. Aside from watering several planters our Weathermatic also fills our fountains and controls the fountain time on as well as the garden lighting. Our new SL1600 replaced our 10+ years old SL1600. A plug and play installation.
June 6, 2020
2 months ago
Quick and Easy
Great Prices and Quick service. Order was delivered in no time.
May 17, 2020
3 months ago
Looks nice!!!!!
Discovered it was not the problem so I now have two working units. Oh well, it looks nice. Hope it works as nice as it looks.
May 8, 2020
3 months ago
Start typing your question and we'll check if it was already asked and answered. Learn More
Browse 43 questions Browse 43 questions and 105 answers
Why did you choose this?
SprinklerWarehouse.com Store
Personal use on property
J E on Feb 22, 2019
I am replacing the same controller with a new model from the same manufacturer.
P N on Aug 5, 2018
Personal use on property
J E on Feb 22, 2019
replacement product, good price
R W on Aug 6, 2018
I am replacing the same controller with a new model from the same manufacturer.
P N on Aug 5, 2018
replace the old one
B O on Jul 22, 2018
Replacement for my 14 year old unit, same one
F O on Jul 19, 2018
reference from a friend
W J on Jun 6, 2018
Replace older unit
K S on Apr 30, 2018
used before
Randy D on Dec 14, 2017
same as above
R L on Sep 17, 2017
Replacing existing failed control system. Like the ability to add extra modules in the future to expand system with additional zones.
michael b on Aug 17, 2017
quality and price
Greg G on Aug 4, 2017
Replacing an old SL1600 unit.
DAVID H on May 27, 2017
My 1600 controller took a lightning strike. I am replacing it with the exact same unit.<br />This unit is easy to program/use.
MIKE H on Apr 23, 2017
replacement product, good price
R W on Aug 6, 2018
replace the old one
B O on Jul 22, 2018
Since the installer of our system has gone out of business, we have some problems which we can't figure out. This first is the location of the battery. Reading the manual on page 17 it talks about the SLW weather station 9V battery. I see nothing that looks like the picture. Where is it located? The rest of the instructions are clear, I think. In the control box it shows a figure of a battery that is all white. Does that mean it needs to be replaced?
A shopper on Aug 16, 2012
BEST ANSWER: Hi, I also have a Weathermatic SL1600 that I installed last year. The reason that you cannot find the battery is that it does not have a battery. Like you, I was suprised also when I found that it did not need a battewry. The Weathermatic SL1600 can remember your settings even if it looses power. Newer electronic devices (including thermostats) that have low power requirements are able to store an electronic charge within their circuitry.
If you unplug your Weathermatic SL1600, then plug it back in, you will see that it remembers your settings.
There are other Weathermatic controllers that do use a 9V battery (e.g. the models that check on the weather forecast) but they are the more complex models.
How do you expand to 12 zones?
A shopper on May 10, 2012
BEST ANSWER: The "Weathermatic SLM4 4 Zone Expansion Module" (just search here for "SLM4") is used to add 4 more zones to the SL1600 timer.

When you buy the timer, it comes with 1 expansion module already pre-installed. Therefore, you get 4-zones right of the bat. But you can add up to 3 more (for a total of 4) expansion modules in this timer giving you a total of 16 available stations.

Installation of each expansion module is simple and takes about 30 seconds. The wiring to add the stations into the timer takes much longer.
How do I set it to manual mode so that all zones go off suquentially as they do in auto mode?
Arthur C on Aug 24, 2013
BEST ANSWER: I'm not sure that I understand the question. Zones are attached to the same programs, start times, and days to water in both manual and auto adjust modes. There is a "Manual Test" mode, where you specify a length of time in seconds or minutes and then flip the dial to run and it will fire off each zone sequentially for the specified length of time.
No display... Power outlet is fine... Sprinklers not coming on?
David S on Oct 9, 2015
BEST ANSWER: First, check that the panel is close correctly, than check the fuse inside the panel,is a little black tube, if not check the transformer leads for 24 volts if not , than the transformer is the problem, if is not the transformer , than make sure the power hook up is correctly installed, if not check the ribbon cable that connects the panel to power supply, other than that it might be a circuit issue inside the mother boad. Green cc
when i turn on my system to zone 1 both 1 and zone 4 come on at the same time is this a problem with the clock or zone valve?
caesar a on Apr 18, 2015
BEST ANSWER: Assuming the wiring in the Smart Controller is correct, back check the wiring at the water control valves. Black is usually common. Check the color wiring is the same at the water control valves and the clock. One colored wiring only to each water control valve. Took me an hour to figure out the wires came apart at the water control valve which is located underground.
How do I obtain a user manual for the SL1600 Smart-line controller?
Norman P on Sep 16, 2018
BEST ANSWER: You can download it from Weathermatic's website, which is weathermatic .com. Click on the resources tab and you'll see a link for manuals and instruction. That's where you'll find the user manual for the entire Smartline series.
How do we turn off system due to rain??
A shopper on Jan 3, 2016
BEST ANSWER: You can simply turn the dial on the controller to "System Off"

Or if you would rather have the controller turn off automatically next time, the addition of an RFS-5 Wireless Rain and Freeze sensor will solve that problem for you.

The SLW5 and SLW1 also have a built in rain sensor.
Weathermatic RFS5 SmartLine Wireless Rain-Freeze Sensor
Weathermatic RFS5 SmartLine Wireless Rain-Freeze Sensor
how can i get an instruction book on line? I have a SL1600. lost my book
Howard A W on Apr 23, 2018
BEST ANSWER: Enter Weathermatic SL1600 SmartLine 4 Zone Modular Sprinkler Timer into Google. One of the top hits has the installation instructions and the owners manual for the SmartLine series in pdf form.
Everything seems to be correct, but the stations become repetitive. We only have 3 stations and all the others are off. We only have the "A" program as working. Our Smartline is SL1600. Why does the program repeat?
Alex J on Jun 13, 2017
BEST ANSWER: Check to see if you have more than one start time programmed
how to clear some of the 8 start times, and some of the zones, while using only 1st start time, and program A?
julius e on Jun 17, 2014
BEST ANSWER: I had the same problem. You have to set start time for program A and then set your run time for the zone. Then go to program B and using your up and down arrows go to 12:00AM and then the word OFF will come up. Do that for each program. It took me awhile to figure it out but finally got it running correctly.
How can I get the basic explanation of how to set up the sprinkling system. I would like the instructions. We seem to be unable to get this to run. What are the areas we need to sequence?
Danna D on Jun 8, 2014
BEST ANSWER: You need to make sure even though unit is plugged in you have a fresh battery installed then go through the sequence date and time watering days run time
Then turn system back to run if you still have a problem try to use manual run if a zone does not come on then there is another problem also is this is an existing system and it has a rain sensor the sensor could be bad
I want to use this product in Europe. Can it work with 230V?
Mikos N on May 16, 2013
BEST ANSWER: Take a look at the Installation Manual on the SprinklerWarehouse site. There are instructions for re-wiring it for 230V. You will have to supply your own cord and plug, as it comes with the standard USA 120V plug.
My fuse burn quickly?
A shopper on May 9, 2017
BEST ANSWER: You must have a direct short or a piece of equipment that is drawing more power than the unit delivers. To isolate remove all devices and hook them up one at a time until you find the problem device. Regards
is this a single wire system?
thomas g on Jul 28, 2016
BEST ANSWER: The base controller has a 4 zone module which would normally use a five conductor single wire to a manifold with four valves or less if not controlling 4 different zones. I have mine set up with an extra module for 4 more zones, so I have two multiconductor wires coming from my controller. This controller will control 4 such modules to control a total of 16 zones. I have been very pleased with mine.
Weathermatic 21024E-10D-H 1 in. FPT In-Line Valve with Flow Control
Weathermatic 21024E-10D-H 1 in. FPT In-Line Valve with Flow Control
Controller panel, no display. Does have power to the unit. replaced battery however the battery ran down... Panel was shut tight. Controller under battery power only would not let me program zones.. only showed 0 zones... As soon as new battery ran down, again no display... Cannot locate a fuse... But if panel runs on battery power only fuse should not be the problem???
David S on Oct 12, 2015
BEST ANSWER: The control panel only runs on battery power when it is removed from the housing or the control panel is swung open to access the valve wiring. When the control panel is closed the indicator "NO AC" in the lower right hand corner of the display should disappear. If it does not then the unit is not being powered. With the control panel open so you can access the wiring, there is a red wire in the upper right hand corner of the unit with an in-line fuse. The control panel is powered by the connector that is directly above the expansion module for zones 13-16. The closed panel makes contact with this connector. One thing to watch out for is that the red wire stays clear of this connector when you close the door or it might prevent the connector from making good contact with the control panel. Closing the panel on this wire could damage the wire and cause the inline fuse to blow.
A shopper on Jun 4, 2015
BEST ANSWER: See for yourself: http://www.sprinklerwarehouse.com/Weathermatic-Controller-Module-p/slm4.htm
can the 1600 be used for 2 wire system?
A shopper on Jul 28, 2014
BEST ANSWER: Yes, the SL-1600 and PL-1600 can both be used for a 2-wire system. You will need to remove the SLM4 expansion module that ships already installed in the SL-1600 and replace it with the SLM48DM Decoder Manager. This will allow you to run up to 48 SLDEC1 single zone decoders, or a blend of the SLDEC2 and SLDEC4 (2 zone and 4 zone decoders).

Also, when installing a 2-Wire system make sure to use ground / lightening protection every 500 feet along the wire path using the SLGDT.
Weathermatic SLDEC1 1 Valve Decoder
Weathermatic SLDEC1 1 Valve Decoder
Weathermatic SLDEC2 2 Valve Decoder
Weathermatic SLDEC2 2 Valve Decoder
Weathermatic SLDEC4 4 Valve Decoder
Weathermatic SLDEC4 4 Valve Decoder
Weathermatic SLGDT Lightning Arrestor
Weathermatic SLGDT Lightning Arrestor
Weathermatic SLM48DM Decoder Module for SL1600 Series
Weathermatic SLM48DM Decoder Module for SL1600 Series
Has anyone used the Valve Locator setting to "chatter" and locate a faulty sprinkler valve? Were you successful in finding the valve?
Eddie A on Apr 17, 2013
BEST ANSWER: Just used it two days ago. I had a valve buried down about 20" after some work man had finished some landscape last year. Holding a hollow plastic pipe to the ground to amplify the noise, I found the valve immediately. "Pinging" works great.
Can I use an older model Weathermatic (6 years old) rain sensor with the SL1600 or do I need to update to a newer model rain sensor?
Bob G on Apr 20, 2019
BEST ANSWER: I replaced everything new when I replaced my SL1600 weathermatic including the modulars Everything works great. Easy to install if you take pictures of the old unit wiring, everything wires up the same. It took me an hour to do the whole system. This was my first time doing something like this. I just took my time. Good luck
Is there a product # for the 1.0A slow burn fuse? I need to order some as I cannot find any in my area.
Gary U on Sep 8, 2017
BEST ANSWER: Good morning, we currently do not have the replacement fuse. You can contact Weathermatic direct and they should be able to help you.
what is the warranty of the proline pl1600 controller?
joseph b on Aug 31, 2017
BEST ANSWER: The PL1600 Controller has as Manufacturer's limited warranty of 2 years.
My unit is set for 1 daily watering cycle. However, it repeats the same cycle immediately after the first cycle is completed! I have to manually turn off when the repeat cycle begins.. Batteries have been replaced,,,,,In the unit , there is only "1 daily start time,",, why the automatic repeat?
A shopper on Jul 18, 2017
BEST ANSWER: Typically, when a controller repeats, it's one of two things. First there could be a second program such as b or c coming on. Make sure there is not any thing entered on the other programs. Second, as mentioned, there should be only one start time for all zones. For example if you want the watering to begin at 6am enter 6 am and the controller will water all zones starting with 1 and cycle through all other zones. Double check that there are no other start times entered.
Does this unit have a seasonal adjust that lets you set say 120% of normal? We get some really hot spells here.
A shopper on May 26, 2017
BEST ANSWER: Yes it does! The adjustment is for 0 to 300% in 5% increments. Each program can be adjusted separately.
How well does the smart link work and how much does it cost for the aircard and one year of service?
A shopper on Jun 14, 2016
BEST ANSWER: The SmartLink enables you to do anything you can normally do standing in front of the controller from any internet device (cell phone, tablet, computer). This allows you to monitor your system and receive alerts if you ever loose power, have a valve short, turn it off if you know there is a storm coming etc...

The fee is $199 per year for a normal subscription, or $320 per year if you choose the flow capable aircard.

Most proven smart / connected controller on the market!

Thanks for asking!
Time to turn on the system for this year. When I turn the dial from daily start time to set watering days the daily start time still displays. When I turn it to set omit watering days and back to set watering days I still get the omit readout. I can't get the set watering days display to read, thus am not able to activate the system. All modes work great on manual. What do I need to do to get the set watering days to display? I have reset and unplugged the unit already.
Ron C on May 31, 2016
BEST ANSWER: I'm afraid you are going to need a new controller. Check the back of the SmartLine panel to see the date code. If it is less than 2 years old you can warranty exchange it.
Is the weathermatic SL 1600 sprinkler control unit 14 day cycle? In Plano, Tx. 75023 we are only able to water sprinkler unit every14 days. Will this unit handle this service?
richard a on Jun 2, 2014
BEST ANSWER: Yes it is capable of running a program on an interval of days. If you will select which program you are using using the PGM button on the upper left hand side of the controller (A,B,C, or D), then turn the dial to the "Days to Water" setting. Under "Days to Water" press the UP button on the upper right of the controller until you get to "Interval". Press "Next" into interval, and toggle to 14 days using the "Up" button.

Hope that helps!!
We have a system with a Weather Matic Lawn Mate 7 that is not working. We have a 3 zone system. Could this unit replace ours?
Susan on Apr 24, 2014
BEST ANSWER: Yes this is a replacement. You need to make sure you have proper zone modules installed in the unit
show me how to reset/progra; my unit?
A shopper on Sep 5, 2012
BEST ANSWER: Please see link for Quick Start Guide to program your controller: https://www.weathermatic.com/download/smartline-quick-start-guide/?wpdmdl=19260&refresh=5d9f441e41b211570718750

To reset your SL1600:
A total reset will clear all programming data in the SmartLine
controller. All settings will return to factory defaults.
• Turn dial to Advanced Menu
• While pressing the UP button, use an open paper clip or
ballpoint pen to push in the Reset switch located on the
back of the operating panel. Release the reset button
while continuing to press and hold the UP button
• Once the display shows CLEARING, release the UP
• Reprogram SmartLine controller
I get intermittent temperature reading faults which I can clear but I'd like to know the probable cause and whether or not these faults need to be cleared to allow for proper operation. Is this a problem? I'm using the wired SLW1 weather sensor and never have an issue with the "antenna" icon on the controller not being on. Thanks for your assistance.
Bob G on Apr 1, 2020
Is there the possibility of purchasing the cover only for the unit?
Pat M on Mar 3, 2019

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