If you’ve had a sprinkler system for more than a season or two, you already know: even the best systems can have hiccups.
Maybe your lawn has a few dry patches. Maybe a sprinkler head looks like it’s trying to launch into orbit. Or maybe your controller is blinking a code you’ve never seen before.
The good news? Most sprinkler issues are common — and if you catch them early, they’re easy (and affordable) to fix. But wait too long? That’s when things get costly.
In this guide, I’ll walk you through the 7 most common sprinkler system problems we see across Maryland — and how you can spot them, solve them, and keep your lawn looking great without breaking the bank.
1. Clogged or Misaligned Sprinkler Heads
The Problem: Heads that spray wildly, shoot into the street, or barely mist the grass.
What Causes It: – Dirt, sand, or debris inside the nozzle – Heads knocked out of alignment by lawn mowers, pets, or foot traffic
What You Can Do: – Turn off the system, lift the head, and clean the nozzle with a toothbrush or spray of water – Realign the head so it sprays in the correct direction (usually just a simple twist)
When to Call TLC: If the head won’t retract or keeps popping off — it may need to be replaced.
Why It Matters: Clogged or misaligned heads can waste water, create runoff, and leave big parts of your lawn dry. If left alone too long, dry patches can turn into dead turf — and that’s a much pricier fix.
Bob’s Tip: Clean your heads once a season. Just like brushing teeth — it prevents big problems later.
2. Leaking Valves or Zones That Won’t Shut Off
The Problem: Water constantly leaking from a head, or a zone that runs long after the controller is off.
What Causes It: – A worn or cracked valve diaphragm – Debris stuck in the valve – Electrical signal failure keeping the valve open
What You Can Do: – Manually turn off the valve using the bleed screw or shutoff – Check for obvious debris or damage
When to Call TLC: If a valve continues to leak, we’ll open the box, inspect wiring, and replace internal parts if needed.
Why It Matters: A single leaking valve can waste hundreds of gallons of water a day — and if it floods low-lying areas, it can also attract mosquitoes, damage roots, or encourage mold.
Bob’s Tip: A running zone can waste gallons per hour. Don’t ignore it — the water bill alone will bite.
3. Zones Not Turning On at All
The Problem: You tell your controller to water… and nothing happens.
What Causes It: – A broken solenoid on the valve – Wiring issue (chewed wire, corrosion, or bad splice) – Controller programming error
What You Can Do: – Check the controller settings for correct start times and days – Test the zone manually – Listen for the click of the solenoid activating
When to Call TLC: We’ll trace the wire, test the solenoid, and check controller output — no guesswork.
Why It Matters: If an entire zone stops working, large sections of your yard could go weeks without watering. We’ve seen front lawns wither in just a week during peak July heat.
Bob’s Tip: Always check the controller battery too. A dead backup battery can erase your schedule.
4. Uneven Coverage or Dry Patches
The Problem: Some spots are lush and green — others look thirsty and worn out.
What Causes It: – Poor head spacing (too far apart or blocked) – Low pressure in certain zones – Heads not popping up fully due to debris or low flow
What You Can Do: – Watch a full cycle — note where coverage is weak – Check for obstacles like tall grass, mulch, or hardscape
When to Call TLC: We’ll assess spacing, adjust pressure, and recommend head changes or additional zones if needed.
Why It Matters: Uneven watering is often the first sign of deeper system imbalance. Don’t just water longer — fix the coverage.
Bob’s Tip: Maryland’s clay-heavy soil can cause water to pool or run off. Water in shorter cycles to let the ground absorb it.
5. Controller Glitches or Programming Confusion
The Problem: Your system doesn’t run when you expect — or runs too often.
What Causes It: – Overlapping start times – AM/PM mix-ups – Faulty rain sensors sending false signals
What You Can Do: – Double-check your start times and durations – Make sure you’re not stacking programs A, B, and C – Bypass the rain sensor to test manual control
When to Call TLC: We’ll reprogram or upgrade your controller, walk you through the features, or install a smart system.
Why It Matters: Overwatering can lead to mold, fungus, and a spike in your water bill — not to mention the embarrassment of spraying your neighbor’s sidewalk every day at 6 AM.
Bob’s Tip: If you’re not a fan of buttons and blinking lights, let us install a controller you can manage from your phone.
6. Leaks at the Backflow Preventer or Main Shutoff
The Problem: Dripping, spraying, or pooling water near the house or valve box.
What Causes It: – Freeze damage (especially after a harsh winter) – Loose fittings or worn seals – Accidental bump from yard equipment
What You Can Do: – Inspect the area after turning the system on in spring – Tighten fittings if possible – Shut off water supply if spraying is severe
When to Call TLC: We’ll replace the backflow device or repair fittings — safely and to code.
Why It Matters: Leaks near your home’s foundation can lead to water intrusion. And Maryland code requires functioning backflow devices to prevent contamination of the public water supply.
Bob’s Tip: Always have your system winterized before the first hard freeze. It’s not optional in Maryland.
7. Pop-Up Heads Stuck or Failing to Retract
The Problem: Sprinkler heads that don’t rise during watering — or don’t go back down afterward.
What Causes It: – Dirt or debris in the stem – Worn or cracked seals – Low water pressure preventing full operation
What You Can Do: – Gently lift the head and clean around the base – Flush the zone to remove debris
When to Call TLC: If heads are cracked or keep sticking, we can swap them out quickly.
Why It Matters: Stuck heads waste water, trip kids or pets, and are often the first part of the system to wear down. Catching this early avoids bigger zone failures.
Bob’s Tip: We recommend replacing heads every 7–10 years, depending on use and soil conditions.
Proactive Maintenance = Peace of Mind
Most sprinkler issues don’t start as expensive problems. They become expensive when ignored.
That’s why we recommend a seasonal TLC check-up:
- Spring Start-Up: We test all zones, heads, and controller programming
- Mid-Season Check: Ensures optimal coverage and detects pressure issues
- Fall Winterization: Protects your system from freezing and costly spring repairs
“An ounce of prevention is worth hundreds of gallons of cure.”
Final Thoughts: You Don’t Have to Be an Irrigation Expert — That’s Our Job
Owning a sprinkler system shouldn’t be stressful. It should feel like the easiest decision you ever made for your lawn.
If something’s not working right, don’t ignore it. And don’t assume it’s going to cost you a fortune.
At TLC, we fix small problems every day before they become big ones. And we always do it with the same honesty, clarity, and craftsmanship that’s defined our work since 1981.
Give us a call, schedule a check-up, or just shoot us a question. We’ll talk you through it — no pressure.
Because healthy lawns grow from healthy conversations.
Warmly,
Bob Carr & The TLC Team