Is a smart sprinkler controller worth it? Savings, wiring and setup
Updated
A smart sprinkler controller can cut outdoor water use by adjusting to weather or soil. Learn what EPA WaterSense says it saves, how to check your zones and wires, and what to do about local watering rules.
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What a smart sprinkler controller does
A clock-based controller waters on a fixed schedule whether it rained yesterday or not. A smart controller adjusts. EPA describes weather-based irrigation controllers as devices that use local weather data and landscape conditions to tailor watering schedules, and soil moisture-based controllers as devices that override scheduled irrigation when the soil beneath the landscape does not need water. Both can be a standalone controller or an add-on to an existing one.
The reason this matters: outdoor use is about 30 percent of household water, and up to 70 percent in hot or dry places, according to EPA. EPA also says residential irrigation uses nearly 8 billion gallons a day in the United States and estimates that roughly half is wasted through overwatering.
What savings to expect
| Type | EPA WaterSense figure | How it decides |
|---|---|---|
| Weather-based controller | Nearly 7,600 gallons a year for an average home, replacing a clock timer | Local weather data and landscape settings |
| Soil moisture-based controller | More than 15,000 gallons a year for an average home with an automatic system | Moisture sensors in the soil |
| Basic Wi-Fi scheduler (not labeled) | No EPA figure | Phone-based schedule, sometimes with a rain delay |
EPA’s page for irrigation controllers says a home can save up to 15,000 gallons per year. Treat these as averages and upper figures: your savings depend on how much you overwater now, your climate, and how you set the plant types and sun exposure. A system that already runs lightly will save less.
Payback arithmetic: EPA’s national estimates (220 billion gallons and $2.5 billion in water costs for weather-based controllers) imply about 1.1¢ per gallon, though your own water rate will differ. At that rate, 7,600 gallons is about $86 a year, so a $150 controller pays back in under two years. At a cheaper water rate, expect longer. Look at your water bill: price per 1,000 gallons, including the sewer charge on outdoor water if there is one.
Check your system before you buy
- Count the zones. Open the existing controller and count the numbered terminals with wires. Add one for any extra zone you plan to use. Buy a controller with at least that many zones; many sizes come in 8, 12 or 16.
- Look for the common and master valve wires. Each valve has one wire to a numbered zone and a shared common wire (often marked C or COM). If there is a pump start relay or master valve, you need a controller with a P/MV terminal.
- Confirm the voltage. Residential valves run on 24 VAC, supplied by a transformer plugged into an outlet or wired to the controller. If the controller is hard-wired to 120 V, turn off the breaker and follow local code; hire a licensed electrician if you are not comfortable.
- Photograph the wires. Take a clear photo of the terminal block before disconnecting anything and label each wire with tape.
- Test Wi-Fi where the controller sits. Garage and basement walls weaken the signal. See extending Wi-Fi to the garage or yard.
- Rule out unusual systems. Two-wire decoder systems, some commercial valves and pump circuits that carry line voltage need a controller built for them or a professional.
Install and set up
- Turn off the sprinkler system, unplug the transformer (or switch off the breaker), and remove the old controller.
- Connect the common wire and each zone wire to the matching labeled terminals on the new controller, following the manual. Connect the transformer’s 24 VAC wires to the AC terminals.
- Restore power and run each zone manually for a minute to confirm which valve opens. Label zones as you go: “front lawn,” “side drip,” “back beds.”
- Enter the plant type, sprinkler type, soil, slope and sun exposure for each zone. These settings drive the watering time.
- Enable “cycle and soak” on sloped or clay-soil zones so water has time to enter the soil instead of running off.
- Walk the yard during a run. Fix broken heads, spray hitting the sidewalk and geysers; no controller can compensate for a leak.
Local rules and rebates
Many cities and water districts limit watering days and hours, especially in drought. Check with your water utility before you set the schedule, and use a controller that can accommodate watering restrictions. EPA notes that many utilities offer rebate programs for soil moisture-based controllers, and some utilities extend rebates to weather-based models too. Search your utility’s website for “smart irrigation controller rebate” before you buy, because some programs require a specific model or a receipt and have deadlines.
When a smart controller will not help much
- No in-ground sprinkler system: a smart hose timer is the equivalent for a hose.
- Drip-only beds: EPA says microirrigation uses 20 to 50 percent less water than conventional sprinklers, so the hardware already saves; a smart controller adds scheduling but less additional water savings.
- A landscape that you already hand-water sparingly.
- Renters and HOA residents: the controller is often part of the building or landscaping contract. Ask first; see can renters install smart devices and HOA rules.
In freezing climates, follow the manufacturer’s winterizing steps: blow out the lines, then switch the controller to its off or rain mode. Before the first frost, shut off the supply to the backflow preventer and drain what you can.
Shop by need
In-ground system on a clock timer, typical lawn
What to look for: WaterSense label for weather-based controllers, enough zones plus spare, watering-restriction settings, cycle and soak, 24 VAC compatible
Typical price: $80–$250
See options on AmazonExisting controller you want to keep
What to look for: soil moisture sensor that overrides the schedule, wireless probe, WaterSense labeled sensor, compatibility with your controller
Typical price: $50–$200
See options on AmazonLarge property with a pump or master valve
What to look for: pump start or master valve (P/MV) terminal, 12 or 16 zones, flow monitoring, outdoor-rated case if mounted outside
Typical price: $120–$300
See options on AmazonController far from the Wi-Fi router
What to look for: external antenna or Ethernet option, schedule stored on the device, offline operation
Typical price: $15–$80
See options on AmazonFrequently asked questions
How much water does a smart sprinkler controller save?
EPA says a WaterSense labeled weather-based controller can save an average home nearly 7,600 gallons a year and a soil moisture-based controller more than 15,000 gallons. Your result depends on how much you overwater now.
Do smart sprinkler controllers work with any sprinkler system?
They work with most standard residential 24 VAC valve systems. Decoder systems, line-voltage pumps and some commercial setups need other hardware. Count zones and check for a master valve before buying.
Do I need a C-wire for a smart sprinkler controller?
Sprinkler controllers use a shared common wire for the valves, not a thermostat C-wire. Make sure the common wire is connected at the controller and the transformer supplies 24 VAC. Photograph the wiring first.
Will a smart controller follow local watering restrictions?
Many can be set to restricted days and hours, which EPA lists as a feature of WaterSense labeled controllers. You still have to enter your city’s rules, and the rules change, so check your water utility’s website each season.