8 Common Sprinkler System Problems (& What to Do About Them)

The top five: it is almost always the head

You will notice a trend.

• A head that is not rotating. Rotors have internal gears, and grit, freeze damage, or age stops them. A stuck rotor waters one narrow stripe and starves the rest of its arc.
• A head that is leaking. Usually a failed seal or a cracked body, and it often shows as a persistently soggy spot or a small sinkhole around the head.
• A head mowed off by a lawn mower. Extremely common and usually obvious. The head sits too high, the deck catches it, and the top is gone.
• A head out of adjustment. Too high, too low, crooked, or aimed wrong. Heads that have settled too low spray into the grass rather than up over it, so the water never carries.
• Nozzles clogged with debris. Grit from the line or soil washed into the nozzle. A clogged nozzle does very little of anything.

Broken sprinkler system: now what

Diagnosing a sprinkler problem can be tricky, because one visible symptom can come from several different causes. The good news is that the top five are all straightforward repairs. Heads get cleaned out, readjusted, or replaced, and the zone goes back to the coverage it was designed for.

It is not a cosmetic repair. When heads are broken, they are not reaching all of your lawn, or they are watering things that do not need water: sidewalks, the driveway, the side of the house. Add a settled head spraying sideways into the turf and a clogged nozzle doing nothing, and you get a lawn with brown areas in a yard where the sprinklers appear to be running fine.

The practical diagnostic is simple and free: run each zone manually, stand there, and watch where the water actually goes. Most coverage problems are visible in 60 seconds per zone.

6. Not enough pressure (or too much)

Pressure problems announce themselves in the shape of the water.

• Too low: water streams out of the head instead of forming a spray pattern. Heads may not pop up fully, and rotors may not turn.
• Too high: you see fine mist instead of a steady spray. Misting means a large share of the water is evaporating or drifting off target before it lands.

Causes range widely: tree roots intruding on a line, a hole in the pipe, a partly closed valve, too many heads on one zone, or a change in supply pressure from the street. Because the causes are so different, this one is worth diagnosing rather than guessing at.

7. A zone is not working

Every zone should turn on and off and run properly so each area of the lawn gets the water it needs. Zones fail for reasons you would never see coming:

• Lightning damage to the controller or field wiring
• A leak or break in the lateral line
• An animal that chewed through wire or pipe
• A failed solenoid on the zone valve
• A wiring connection that corroded in a valve box

When a zone is dead, the grass above it turns brown and may die, and that is a reseeding job on top of the repair. This is the failure that most rewards catching early.

8. Is it a leak, or is it the controller?

High water use gets blamed on leaks, and sometimes that is wrong. Before you start digging, check the controller.

A controller set to run too many start times, or still running a spring schedule in August, will raise your bill with nothing broken anywhere. The same goes for a schedule that was never adjusted after a smart controller lost its program or after a power outage reset it to a default. If it is not set correctly, you are either overwatering your landscape or underwatering it, and both show up in the lawn.

Rule out the schedule first, then look for a leak. A meter check with all irrigation off is the quickest way to confirm whether water is actually moving when it should not be.

Catch them early

Most homeowners do not look closely at their sprinkler systems, so the small warning signs go unnoticed and turn into bigger problems later. Spring is when they surface in Eau Claire and the Twin Cities, because a winter of frost heave leaves heads off arc and cracked bodies behind, and the first cycles in May are when that gets found. By the time the system obviously needs repair, it is an emergency: the grass is browning and expensive plantings are stressed.

That is the argument for a sprinkler system maintenance plan. A specialist finds the broken heads, the drifted adjustments, and the failing zone valve before the lawn pays for them. Beyond repairs, the same visits produce advice that saves water: whether you are watering too much or too little for the season, and what updates would make the system run more efficiently. Ignoring maintenance regularly costs more than maintenance does.