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Weathermatic SL1600 4 Station Expansion Module | SLM4

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Sales Price $52.64 Our Price $92.95 You save 43%



The Weathermatic SLM4 4-Zone Module is only to be used with the PL1600 & SL1600 Controller.

SMARTLINE controllers each represent the richest feature set in their respective class. By adding an SLW Series On-Site Weather Station; a SmartLine controller enters a class of its own. It has been said; "You buy the product only once; but you buy the water every month." This fact alone is a great reason to invest in SmartLine. With no service provider dependence; no recurring maintenance; and no user fees; SmartLine pays dividends on your one-time investment every single month.

SmartLine controllers and SLW Series On-Site Weather Stations deliver an excellent ROI (Return On Investment) through a patented water saving process (U.S. Patent No. 6;314;340).


  • SL1600 SmartLine Controller
  • SLM4 SmartLine 4-Zone Module
  • SLW10 Residential On-Site Weather Station
  • SLW15 Wireless On-Site Weather Station
  • SLW20 Commercial On-Site Weather Station

SmartLine takes weather readings, like temperature and rainfall, every 8 seconds to develop the optimum watering schedule for the plants and turf. By making 365 annual adjustments, rather than 0-12 adjustments, SmartLine reduces water usage by 20-50%, improves plant health and beauty, eliminates runoff, and puts an end to water worries.

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  • Indoor/Outdoor rated with mounting bracket included
  • Hot-swappable modules can be added/removed without resetting or unplugging the controller
  • Backlit LCD and door latch on SL1600; SL1624; SL 4800
  • 2 run modes: Standard mode runs user input zone run times; Auto Adjust mode requires SLW Series On-Site Weather Monitor to calculate weather based run times in replacement of user input zone run times
  • Rain/Freeze sensor bypass/active button located on face panel displays sensor status with red/orange/ green tri-color LEDs (red indicates sensor is prohibiting irrigation; orange indicates paused for run/soak or zone-to-zone delay; green indicates normal operation)
  • 4 programs: A; B; C; program D can operate concurrently.
  • 8 start times per program
  • Non-volatile memory retains programs in the event of power outage
  • Zone run times settable from 1 minute to 9 hours 55 minutes with operation count down displayed in hours; minutes; and seconds (zone run times replaced with weather based calculated values in Auto Adjust mode)
  • Watering day selections of custom days of the week; odd/even; or interval days
  • Omit settings of omitting times of the day; omitted days of the week; and up to 7 omitted calendar dates
  • All models except the SL800 are outdoor/indoor rated with a mounting bracket included.
  • Seasonal % adjust by program; by month for simple year-round water budgeting (monthly percentages not used in Auto Adjust mode)


  • On-board Multi-Meter performs diagnostic test function by displaying electrical readings for each solenoid in milliamps (mA); transformer 24V power reading (V); and 9V battery voltage (V)
  • Built-in Valve Locator - locate hidden valves by simply listening for the audible chatter of the solenoid created by a unique electrical current
  • Run/Soak Settings - virtually eliminate runoff by setting the maximum allowable run time (1 - 30 min.) and required soak time (1 min. to 2 hrs.) for each program.
  • Progammable delay feature suspends watering from 1 to 7 days.
  • Zone to zone delay programmable from 1 min. to 3 hrs.
  • Master valve to zone delay timing sequence is settable for master valve activation (1 sec. to 1 min.) and deactivation (1 sec. to 3 min.)
  • Clear program function to delete all program settings
  • Review menu displays accumulated ET deficits by zone (displayed in inches) and the corresponding zone run times for the next available run time
  • Built-in Valve Locator - Locate hidden valves by simply listening for the audible chatter of the solenoid created by a unique electrical current *
  • On-Board Multi-Meter - Displays the electrical current reading of each zone for quick troubleshooting and a proactive approach to maintenance *
  • Master Valve/Pump Settings - Achieve hydraulic control with settings for zone to zone delays and master valve timing *
  • Manual Test Settings in Seconds - Complete a walk-thru in a fraction of the normal time by running a manual test set to as little as 10 seconds/zone


More Information
Brand Weathermatic
Warranty 2 Years
Type Expansion Module
Controller Compatibility Weathermatic SL1600 Controller
Station Expansion 4