Irrigation Pump Losing Pressure? 7 Things to Check

The irrigation system is still running, but something has changed.

Sprinklers do not reach as far.

Pressure starts normally and then drops.

One zone works well while another struggles.

If you have an irrigation pump losing pressure, the pump itself may not necessarily be the problem.

Water source conditions, suction piping, valves and the distribution system can all affect the pressure you see downstream.

Why Is Your Irrigation Pump Losing Pressure?

Before replacing equipment, work through the system.

1. Check the Water Level

A pump cannot move water that is not available.

Ponds, tanks, wells and other water sources can change significantly during the summer.

As the source level falls, conditions at the pump inlet can change too.

If performance decreases as the season progresses, source water level is one of the first things worth checking.

2. Look for a Suction-Side Air Leak

A small suction leak may draw air into the system without producing an obvious water leak.

That makes these problems easy to miss.

Check accessible fittings, gaskets, seals and connections for possible air entry.

Air entering a centrifugal pump can interfere with stable operation and reduce performance.

3. Inspect the Suction Strainer

Outdoor water contains debris.

Leaves, algae, sediment and other material can accumulate around an inlet or strainer.

A partially blocked strainer restricts the amount of water reaching the pump.

If pressure gradually declined rather than disappearing suddenly, inspect the suction side carefully.

4. Confirm Valve Positions

Someone may have moved a valve.

A valve may also have been left partially closed following service.

Check both the suction and discharge sides of the system.

A restriction that seems minor at low flow can become much more noticeable when the irrigation system demands more water.

5. Check the Distribution System for Leaks

Sometimes the pump is producing adequate pressure and the system is losing it farther downstream.

Look for broken piping, damaged irrigation heads, open bypasses, restricted filters or unusually high demand.

If one zone behaves differently from the rest, that can help narrow down where the problem is located.

6. Consider Impeller Wear

Water containing sand or abrasive material can gradually wear pump components.

The pump may still run.

The motor may sound normal.

But over time, a worn impeller can affect how much pressure and flow the pump is capable of producing.

This is one reason an irrigation pump losing pressure should be evaluated based on actual performance, not simply whether the motor turns on.

7. Ask Whether the System Has Changed

Have additional zones been added?

Has piping been extended?

Is more water being demanded than in previous seasons?

A pump operates according to the conditions of the system connected to it. Changes to piping, valves, flow requirements and elevation can all change how the pump performs.

Don't Replace the Pump Until You Know the Cause

Pressure loss is a symptom.

The cause could be the water source, a suction leak, a restriction, worn components or a problem in the distribution system.

Replacing the pump before identifying that cause can leave you with new equipment experiencing exactly the same problem.

Academy Pump & Motor provides pump sales, service and repair for commercial, industrial and water-handling applications throughout Calgary and surrounding areas.

Irrigation pump losing pressure? Call Academy Pump & Motor at 403-437-7888 or visit academypump.ca.