If a home inspection turns up problems in a home’s irrigation system, the good news is that repair or replacement is generally relatively simple and inexpensive since problems usually affect only specific areas of the system. Common problems include:

Drip heads: Drip heads are low-lying emitters that allow water to continuously drip into the root zone, preventing evaporation and keeping young or non-established roots moist throughout the season. If they are missing or broken, water will not be directed where desired. Drip heads are easily damaged by lawnmowers, pets, landscaping tools and even lawn games like croquet. However, they are easy and inexpensive to replace.

Broken or damaged lines: many irrigation systems use PVC pipes, which are easy and inexpensive to install, but not as durable as metal pipes. Common installation mistakes include installation too near the soil surface leading to potential freezing or damage by shovels; or leaving them exposed to sunlight (UV light deteriorates PVC). Fortunately it’s easy to replace a broken or cracked section of PVC piping: just use a reciprocating saw to cut the damaged section out, and use connectors and a new piece of pipe to replace it, securing both ends with PVC glue.

Solenoids: solenoids control water flow to designated areas within an irrigation system. For example, you may have a separate valve to drip-irrigate newly planted trees, and another valve to allow water flow to the lawn sprinklers. Solenoids are magnetically controlled devices within these valves. Their function is to open and close each valve independently of the others: for example, you may wish to run a drip irrigation system full-time throughout the season (this valve would remain open full-time), but only run the lawn sprinklers every other morning (requiring that this valve be closed except when you want the sprinklers on). If a solenoid fails, you won’t be able to control water flow to specific areas within the system. In this case, the solenoid must be replaced:

  1. Turn off the water supply.
  2. Turn the irrigation system off at the control panel
  3. Locate the solenoid and valve assembly by gently using a soil probe (you’ll hear a hollow sound when you hit it)
  4. Carefully remove the soil from the top of the valve box; remove the lid of the valve box
  5. Unscrew the wire nuts from the solenoid wires
  6. Remove the screws on the valve’s top assembly
  7. Remove the top assembly from the main valve body
  8. Place the top assembly onto a workbench (to avoid losing small pieces in the grass)
  9. Remove the screws that secure the solenoid to the top assembly
  10. Remove the solenoid housing; inspect it for damage and replace if needed
  11. Remove the spring assembly and plunger from the solenoid and check them for damage
  12. Clean any debris from non-damaged parts; replace damaged parts
  13. Reattach the repaired/replaced solenoid housing to the top assembly
  14. Reattach the top assembly to the main valve body
  15. Reattach the solenoid wires to the wire nuts to connect to the irrigation control panel
  16. Turn on the main water supply
  17. Turn on the irrigation system at the control panel
  18. Test the system
  19. If all is working, place the lid back on the valve box, and cover the box with soil

Videos on Irrigation Maintenance and Repair