How do I fix low pressure in my sprinklers?

Low sprinkler pressure in New Brunswick is usually caused by one of four things: a partially closed valve, a pressure regulator issue, a leak in the system, or clogged sprinkler heads — and most of these you can diagnose yourself before calling a pro.

Start with the Simple Checks

Before assuming the worst, walk through the basics. First, check that your main shutoff valve and backflow preventer are fully open — a valve turned even 25% closed can dramatically reduce pressure throughout the whole system. Second, check your home's water pressure at an outdoor hose bib with an inexpensive pressure gauge (available at any hardware store). Residential irrigation systems need roughly 40-65 PSI to operate properly. If your home pressure is below 40 PSI, the problem may be your municipal supply or pressure regulator, not the irrigation system itself.

Isolate the Problem Zone

Run each zone individually and note which ones have low pressure. If it's all zones, the issue is upstream — the main valve, backflow preventer, or your home's water pressure. If it's one specific zone, you're likely dealing with a leak, a broken head, or too many heads on that zone for your supply pressure to handle.

Walk the affected zone while it's running and look for: heads that aren't popping up fully, soggy wet patches between heads (a sign of an underground leak), or heads spraying erratically. A single cracked lateral line can bleed enough pressure to make the whole zone underperform.

Clogged Heads Are the Most Common Culprit

In NB's sandy coastal soils (Shediac, Miramichi area) or after spring startup, debris and sediment frequently clog sprinkler nozzles. Pop a head out of the ground, unscrew the nozzle, and rinse it under a tap. This takes about two minutes per head and often solves the problem entirely. While you're at it, check that the head isn't tilted or sunken — heads that have settled below grade won't pop up with enough force to rotate or reach their intended coverage.

NB-Specific Timing Note

If you're troubleshooting after spring startup, remember that irrigation lines in New Brunswick must be buried at least 300-400mm deep and blown out each fall. If a line wasn't fully winterized, a frost crack from last winter could be your pressure culprit — even a hairline crack bleeds significant pressure underground without being obvious on the surface.

When to Call a Pro

DIY is fine for cleaning heads, checking valves, and basic diagnostics. But hire an irrigation technician if you suspect an underground leak (you'll need a locator and proper pipe repair), if your pressure regulator needs replacement, or if a zone was improperly designed with too many heads for your supply line size. Irrigation repairs in NB typically run $75-$200 for a service call, with underground leak repairs ranging $200-$600 depending on depth and access.

New Brunswick Landscaping can match you with a local irrigation professional for a free estimate — it's a free service covering all of NB.