Sprinkler System Troubleshooting for Beginners

Sprinkler systems tend to work quietly in the background until the day they don't, and when a zone suddenly stops watering or a head starts spraying somewhere it shouldn't, it's not always obvious where to start looking. The good news is most sprinkler problems fall into a small number of categories, and each one has a fairly distinct set of clues.

Problem 1: A single zone won't turn on

If one zone stays silent while the rest of the system runs fine, the issue is usually isolated to that zone's valve or wiring rather than the whole system.

What to check:

• Go to the valve box for that zone and manually turn the bleed screw to see if the valve opens and water flows when triggered by hand. If it does, the issue is likely electrical, either the wiring to that valve's solenoid or the controller station for that zone.
• Inspect the wire connections at the valve for corrosion or a loose connection, especially if the valve box has been sitting in wet soil.
• Test the zone from a different station on the controller if your system allows it, to rule out a bad controller output.

If manually opening the valve doesn't produce water flow at all, the valve itself, or a blockage before it, is more likely the culprit.

Problem 2: A broken or damaged sprinkler head

This is the most common and most DIY-friendly sprinkler issue. A head that's cracked, knocked sideways by a mower, or spraying at the wrong angle is usually a quick swap.

How to fix it:

1. Run that zone manually so you can see exactly which head is misbehaving and how.
2. Dig around the base of the head carefully to avoid damaging the supply line beneath it.
3. Unscrew the damaged head from the riser or pipe fitting.
4. Screw in a replacement of the same type and adjust the spray pattern and radius per the new head's instructions.
5. Run the zone again to confirm proper coverage and check for leaks at the new connection.

Problem 3: Low pressure across the entire system

If every zone seems weaker than it used to be, rather than just one head or one zone, the problem is more likely upstream of the individual zones.

Common causes:

• A partially closed main shutoff valve for the irrigation system
• A clogged backflow preventer or filter screen at the system's main connection
• A leak somewhere in the main line feeding all the zones, which would also show up as an unusually wet or soggy area in the yard
• A well pump or municipal supply issue, if your home relies on either for irrigation water

Start with the simplest explanation: confirm the main shutoff valve is fully open and check any filter screens for debris. If pressure is still low across every zone after that, and especially if you notice a soggy patch of lawn that isn't explained by watering schedule, you may be dealing with a leak in the main supply line rather than anything at the individual zone level.

When to stop troubleshooting on your own

A single broken head or an obviously loose wire connection are reasonable DIY fixes. But a bad valve that needs replacement, wiring that runs back to a controller you're not confident diagnosing, or a suspected leak in the buried main line are different territory, since digging into the wrong spot can create a bigger leak than the one you started with.

If you've worked through the basics and the system still isn't behaving the way it should, ProFlow Plumbing can trace the issue back to its source, whether that's a failing valve, a wiring fault, or a leak hiding somewhere under the lawn, without you needing to dig up half the yard guessing.