Today we’re replacing the diaphragm of a jar Top valve. This is the Irritrol Jar top valve. The procedures we’re doing here will be practically the same for most jar top valves. If your valve box is large enough to allow you to work inside then you can do this entire procedure without pulling the valve box. If the valve box is too small to work inside you may find it easier to dig out the valve box.

How To Replace The Jar Top Valve

Before you begin, you need to turn off the water to your irrigation system at the backflow device or at your main valve, which is often located near the water main. And you need to relieve the pressure in the system by turning on one zone or unscrewing the solenoid one-half turn. For demonstration purposes, we have cut out the side of this valve box. Unscrew the top of the valve.

We’re not replacing the solenoid this time so we’ll leave the wiring intact. To avoid getting debris inside the valve we’re cleaning the valve with a paper towel. Now remove the spring. And the diaphragm Now install the new diaphragm. On many valves, there may be a hole something in the diaphragm that needs to be lined up in a certain direction.

However, on this Irritrol jar-top valve the hole is directly in the center so you only have to worry about getting it right side up. Put the new spring in place. Screw down the collar, test your system, and replace your valve box cover.