Every time you turn on your sprinkler system and the heads pop up to water your lawn, a pump is responsible for providing them with a steady water supply needed to maintain your lawn green and landscaping watered. When the pump no longer performs properly, water flow is significantly reduced, and it may not reach the entire area requiring irrigation.
Some irrigation problems are easy enough to fix yourself if you have a fundamental understanding of how each component of your system operates, while others may require the assistance of a professional. Here are some troubleshooting options for common pump issues:
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Problem 1: Pump Won’t Start or Run
If your sprinkler system is on but the pump doesn’t seem to be getting any power, a good place to start is to make sure the fuse or circuit breaker is not blown or tripped. If you reset the breaker and the problem is still not fixed, you may have an issue with the wiring running to the pump, such as loose wires and connections, or the motor may have shorted out. Check the voltage at the pump motor and pressure switch to identify which, if any, wires are loose and need to be fixed.
Other possible causes of this problem include the irrigation controller and/or the pump start relay, which is used to send power to the pump. If you suspect a problem with one of these components, contact a licensed irrigation contractor who is experienced in fixing electrical issues to make sure you don’t injure yourself or damage the sprinkler system.
Problem 2: Water Doesn’t Reach the Entire Landscaped Area
If your sprinkler pump is on and moves water, but not enough to cover the entire lawn and landscaping, one possible cause is the suction pipe above the water line is not airtight, and the pump is sucking air through small cracks around the joints. The same thing can happen if the pipes are smaller than the suction pipe and discharge connections, which creates friction and low water pressure. You can easily fix this by putting in place pipes with a larger diameter to allow more pressure to reach the entire irrigation system.
Problem 3: Pump Sounds as If It Has Rocks in It
The increased velocity of water entering the pump system and temperature changes can cause some of the water to vaporize, creating bubbles entrained in the liquid. As the pressure of the water continues to rise and drop, these newly-formed bubbles start collapsing violently, producing a rumbling or cracking noise that gives the impression of gravel passing through the pump.
This process is called cavitation, and aside from being noisy, it can be sufficiently violent to physically damage the system components. Depending on the pumped water quality and duration of cavitation, the damage it causes to the sprinkler pump ranges from minor pitting to complete failure. Cavitation can also be caused by having an elbow or a check valve too close (in the last two feet) to the inlet of the pump or if you’re running the pump with too much flow and not enough back-pressure.
Problem 4: Pump Will Not Prime
Lawn sprinkler pumps are centrifugal, which means they use an impeller to draw water in through a larger pipe and push it out through a smaller one. If air or gas accumulates in the impeller’s eye as a result of the pump casing having lost its prime, you run the risk of burning out your pump motor and causing major damage to your entire system.
A pump that repeatedly loses its prime during irrigation cycles may have a leaking mechanical seal, a leak in the suction line, debris clogging the suction screen, or a leaking foot valve. Priming a sprinkler pump simply means filling up the pump casing and suction piping with water, turning on the pump switch, and ensuring there is no air in the inlet line. Please note that even self-priming pumps require at least the pump casings filled with water before they can start operating.
No matter what issues you are facing with your irrigation pump, keep in mind that pumps older than five years may have sustained damage from wear and tear, and their performance may have decreased. So before you decide to install a bigger pump because your system doesn’t perform as well as it should, consider simply replacing the old pump with a new one. Buying a bigger pump when you really don’t need one will only result in wasted money on higher electricity bills.
If you believe your pump may be to blame for your irrigation issues but have trouble diagnosing the cause, you should contact an experienced irrigation contractor that also offers sprinkler pump repair services. Irrigation water pumps are a crucial component of your sprinkler system, and maintaining them properly will ensure the success of your irrigation efforts.
Former U.S. Coast Guard and Tampa-native Joseph Swett is the owner of Sunrise Irrigation, a Palm Harbor-based company that has been providing sprinkler and irrigation services in the Tampa Bay Area, Florida, for more than 20 years. A RainBird-trained landscape specialist, Mr. Swett is dedicated to helping Florida homes and businesses implement effective irrigation technologies and transition towards smart water conservation. In his spare time, Joe sponsors and plays in two men’s softball leagues, but also enjoys surfing and going fishing with his family.