Mr Sprinkler Repair

Sprinkler Repair

Mr Sprinkler Repair

Sprinkler Repair


How to Fix a Bad Sprinkler Solenoid

A malfunctioning sprinkler solenoid can disrupt your lawn’s irrigation system, resulting in dry spots or excessive water in areas of your garden. If you suspect your sprinkler solenoid is bad, here’s a step-by-step guide to diagnose and repair the issue effectively.

Tools and Materials Needed:

  • Multimeter
  • Replacement solenoid (if necessary)
  • Screwdriver
  • Adjustable wrench
  • Teflon tape

Step 1: Locate the Solenoid

Typically, the solenoid is attached to the valve box of your sprinkler system. You might have to dig around a bit if it’s buried under soil or mulch.

Step 2: Safety Precaution

Before you start, make sure to turn off the water supply to your sprinkler system to avoid getting soaked while working.

Step 3: Test the Electrical Connection

  • Use a multimeter to test the electrical connection to the solenoid. Disconnect the solenoid from the wire nuts or terminals.
  • Set your multimeter to the resistance (ohms) setting and measure the resistance across the solenoid’s terminals. A healthy solenoid typically shows a resistance between 20 to 60 ohms. If the reading is significantly higher or lower, the solenoid might be defective.

Step 4: Inspect for Physical Damage

Look for visible signs of damage, such as cracks, corrosion, or any signs that the solenoid has been compromised.

Step 5: Check the Plunger

  • Unscrew the solenoid from the valve body using your hands or an adjustable wrench if necessary.
  • Inside, you’ll find a plunger that can become stuck either open or closed, leading to system failure. Clean any debris around the plunger and the solenoid’s seat.
  • If the plunger is damaged, it’s best to replace the entire solenoid.

Step 6: Replacement

If you’ve determined the solenoid is indeed faulty, it’s time to replace it. Here’s how:

  • Remove the old solenoid by unscrewing it from the valve.
  • Apply Teflon tape to the threads of the new solenoid to ensure a watertight seal.
  • Screw the new solenoid into place, hand-tightening it before giving a slight snug with an adjustable wrench. Be careful not to over-tighten as this could damage the new component.
  • Reconnect the electrical wires using waterproof wire connectors.

Step 7: Test the System

Turn on the water supply and test the irrigation system to ensure the new solenoid is functioning correctly.

Repairing a bad sprinkler solenoid is usually a straightforward task that you can do yourself with basic tools and a little bit of know-how. Always consider safety first by ensuring the water supply is turned off before you start your repairs. If you’re not comfortable working with electrical components, it’s advisable to consult with or hire a professional.

Remember, regular maintenance of your sprinkler system can help prevent solenoid and other system failures, saving you time and money in the long run.


If you have any questions or need any type of sprinkler system repair, the experts at Mr Sprinkler Repair will be glad to help. Give us a call or 855-695-1000 to set an appointment.