Why Does My Sprinkler System Skip a Zone?

Homeowners are constantly tested by the time and energy it takes to stay ahead of owning a home, and landscape maintenance is no exception.

A sprinkler system simplifies watering and soil moisture management. Most homes nowadays have sprinkler systems already installed, and if that system is functioning properly it can be easy to forget it’s there. However, the moment something breaks, the convenience of automated watering is lost and now you’re stuck with a frustrating problem with your irrigation system.

One issue that can occur is the system skipping a zone. Unless you monitor your system’s performance on a regular basis, a skipped zone can be easy to miss. There are a few possible reasons this problem is occurring:
• Leaks: a loose connection or break in the supply line will prevent water from reaching the heads.
• Controller issues: a malfunction in the controller or wiring issue can also be the cause.
• Valve issues: various problems can arise with zone valves that will impact a zone’s water supply.
• Pump location (if present): if your system utilizes a pump to supply the irrigation system, and that pump isn’t within a few feet of your water source, air can enter the supply line and interrupt the flow and pressure of the water.

Signs Your Zone Is Skipping or Failing

• Zone doesn’t turn on at all
  • Weak spray or low pressure in one zone while others are normal
  • Water pooling near valve boxes
  • Buzzing or humming noises from the pump
  • Multiple zones failing at once, often pointing to a common wire problem

What is a Skipped Zone?

Before we can get into the why of it all, it’s necessary clarify what it means for a zone to be skipped.

Automated irrigation systems are organized into zones. Each zone covers a section of the landscape, and while these zones are a part of the same system, they operate independently from the others. If a zone never activates or fails to deliver water to its section, it is being skipped. The system still runs, and other zones appear to be working properly, but one (or multiple) zones seem like they don’t ever turn on.

There are several possibilities as to why a skipped zone would occur.

How Zones Work in Irrigation Systems

Zones function through a series of components that work in sequence:

Controller → transformer → solenoid → diaphragm/valve → water line → sprinkler heads

If one part fails, an entire zone can stop working.
• Single-zone failures often point to wiring or valve issues.
• Multi-zone failures are more likely tied to the controller, pump, or main supply.

Common tools for diagnosing issues include a multimeter (to test voltage/ohms), screwdrivers for valve adjustments, and waterproof wire connectors for repairs.

Water Line Leaks

The very first, and easiest, place to start when diagnosing a skipped zone issue is to check for leaks. If the water lines in a zone have a leak, it will negatively affect the pressure required for the zone to function.

Finding a leak can sometimes be easy, and sometimes not. Visual inspection of the system, while it’s running, can often indicate if a leak is present. Key indicators if the leak is present include, water pooling in an area of the yard, dead spots (or even overgrown spots), or overly soggy areas.

Fixing a line leak that is easy to spot is a fairly straight-forward repair. However, if a leak is not easily seen without digging, finding that problem area will take a bit more effort. Luckily the experienced techs at Andy’s Sprinkler, Drainage & Lighting have plenty of tricks up their sleeves to find a leak with minimal impact on your yard.

Controller Issues

If a leak is not easily identifiable by visual inspection, the controller is the next place to look. An irrigation controller is the brains of the system and is essentially a small computer that manages watering schedules and sends low voltage electrical signals to the valves to open.

Using an electrical meter, the Andy’s tech will test the controller’s voltage and ohms directly at the source. If levels are outside the normal range (or not present at all), a wiring issue is the likely culprit.

Other potential issues can exist with a controller that could cause a zone skip issue, and a thorough test of the controller’s functionality will indicate if that is the source of the problem.

Additional Controller-Related Causes

• Solenoid failure (loose, dirty, or broken)
  • Low voltage or transformer malfunction
  • Common wire failure in the daisy chain
  • Misprogrammed or factory-reset schedules
  • Faulty backflow preventer reducing flow
  • Too many sprinkler heads in one zone (overload)
  • Indexing valve or pump suction problems introducing air

Valve Issues

Once the electrical signal is sent from the controller to a zone’s valve, a properly functioning valve will open, allowing the pressurized water to charge those zones lines. Once a zone’s proper charge is reached, the heads will activate and your landscape will be watered once again!

If any process within the valve malfunctions, the water supply needed for a zone to operate will be affected. Several tests will need to be conducted at the valve to figure out if the zone skip is caused by the valve or not.

How to Troubleshoot at Home

• Test voltage and ohms with a multimeter
  • Open the manual bleed screw to see if valve opens
  • Swap zone wires at the controller to confirm if problem is valve vs controller
  • Re-splice or replace corroded common wires
  • Inspect the flow control on valves for proper adjustment
  • Clean or replace solenoids if dirty or burnt out

Pump Problems

For irrigation systems using a natural water supply source (well, lake, etc.), a pump is necessary in order to pressurize the water so the system can run properly. Issues with pump-driven systems can range from simple (clogged intake or a crack in the line) to complex (over-cycling or pressure imbalance). If you have a lake-fed water supply, Andy’s Sprinkler, Drainage & Lighting can typically help with most issues. If your pump is in a well, a pump specialist is recommended prior to any irrigation service.

Pump Repair and Prevention Tips

• Replace solenoids, diaphragms, or valves when faulty
  • Clean clogged valves or sprinkler heads regularly
  • Relocate pump closer to water source if airlocks persist
  • Use waterproof wire connectors to prevent corrosion in pump wiring
  • Schedule annual inspections to catch pump, wiring, or valve issues before they escalate

If Your Sprinkler System Skips a Zone, We Can Help You Fix It

There are plenty of reasons why a sprinkler system might skip a zone, but we know sprinkler issues can be frustrating and the reasons why are probably less important than “how quick can you fix it?”. Maintaining your landscape and the soil moisture around your home is an important part of homeownership, and Andy’s is here to help!

Schedule an appointment with Andy’s Sprinkler, Drainage, and Lighting for all of your sprinkler system needs.

How Much Does It Cost to Fix a Skipped Zone?

• Controller replacement: typically ranges between $200–$350
  • Solenoid or diaphragm replacement: usually $15–$50 for parts
  • Average professional irrigation repair: $150–$400 depending on complexity
  • Plumber or irrigation tech hourly rates: $50–$100 per hour

DIY repairs are possible for simple fixes like re-splicing wires or replacing solenoids. For more complex electrical or underground issues, Andy’s expertise ensures repairs are safe and long-lasting.