Expert IrrigationA valve is the part that decides whether a zone runs, and it is the single most common thing we replace in Broward. The failure modes look different from the outside but almost all of them come down to three components: the solenoid that receives the signal, the diaphragm that does the sealing, and the wiring between the controller and the box.
The zone will not come on
Three usual causes, and they are quick to separate. A failed solenoid reads outside the healthy range of roughly twenty to sixty ohms — open circuit means a broken coil or a cut wire, near zero means a short. A controller output stage that no longer fires will test dead at the terminal while every other zone works. And a diaphragm that has swollen shut will hold pressure even when the solenoid is energised. We test at the controller first and at the valve second, because walking straight to the box is how people end up replacing a healthy valve.
The zone will not shut off
This one costs real money, because the system keeps running after the cycle ends and often after you have gone to bed. The usual culprit is debris under the diaphragm holding it fractionally open, or a diaphragm that has gone brittle and no longer seats. Occasionally it is the solenoid plunger sticking. On well-fed systems we see it more often, because sand and iron particles are working through the valve every cycle. If a zone is running continuously, shut the valve manually at the flow control or close the mainline before you do anything else — a stuck valve can put thousands of gallons through in a night.
Weeping and low pressure at the heads
A valve that leaks past its seat lets a trickle through constantly. You will see a permanently damp patch near the lowest head on the zone, and often algae or moss on the hardscape nearby. It also drops the pressure available to the rest of the zone, so heads mist rather than throw. People usually blame the heads for this and replace them, which does not fix it.
What we find in Broward specifically
Valve boxes here sit in full sun in a subtropical climate, and diaphragm rubber does not enjoy that. Cooking is the normal end of life rather than the exception, which is why a fifteen-year-old system usually needs diaphragms rather than a whole new valve body. The other regional pattern is water quality: on shallow wells, iron and fine sand score the seat and shorten diaphragm life considerably compared with a city-water system on the same street.
Repair or replace
If the body is sound and the threads are good, a diaphragm and solenoid rebuild is the cheaper answer and lasts years. We replace the whole valve when the body is cracked, when the threads have been damaged by previous repairs, or when it is a discontinued model with no parts available — which is common on systems that predate the current mainstream lines. We will tell you which one you are looking at before we quote, and the price is firm before anything comes apart.