Swimming Pool Blog

Jandy Valves - Deconstructed

Jandy Valves - Deconstructed
by Rob Cox, July 11, 2011

Jandy Valves: A look inside, How they Work

Jandy Valves, How they work, a look inside


The Jandy Valve revolutionized pool plumbing when it was introduced in the early 80's. They were white at first, then grey, and now for about 20 years, a sleek black design for the Never Lube Jandy Valve (Jandy Grey valves require periodic lubrication by filling a grease cap).

Over the years, I have found that many pool owners, having never looked inside of a Jandy Valve, have trouble understanding how they work. Jandy Valves are quite simple, as I hope this blog post will demonstrate. jandy valve schematic diagram



Starting at the bottom of our Jandy Valve Parts Breakdown shown on the left, a Jandy Valve consists of the valve body, the valve diverter, 3 o-rings, cover or lid, handle, locking knob and the cover screws.

As the schematic shows, the handle locks onto the notched stem of the diverter. As the handle is turned, the diverter turns in the identical direction. The width and curvature of the diverter, which I sometimes call a "door", matches the handle exactly. The handle grooves match the stem so that the handle will always be installed directly above the diverter.

There are stops on the valve cover to prevent over-rotation or "dead-heading" the inlet, or completely blocking water flow. 3 way valves have a travel of 180 degrees, and2 way valves rotate only 90 degrees.

jandy valves explained

Jandy Valves, and other 3 way valves are very simple to make adustments to your water flow. For instance many pool owners keep the main drain line 1/2 closed, and the skimmer wide open. If you have two or more skimmers, you can throttle back the skimmers closer to the pump, to allow more suction to the further away skimmer(s).

The jandy valve shown at the right has one port half way closed, or halfway open - depending how you look at it ~ If 100 gallons per minute were flowing through both incoming ports, closing one halfway would give 75 gpm flowing through the open port, and 25 gpm flowing through the halfway closed port.


Jandy Valve Maintenance: Not much needed, but here's a few jandy valve care and repair tips.

1. If leaking air or water around the stem, replace item #6, o-rings, and lubricate.

2. If the valve body or diverter is cracked, replace the entire valve, save extra parts.

3. If you want to prevent a valve from being turned, remove and store handle.

4. Older Jandy valves require some lubrication, use Magic Lube or other silicone lubricant.

5. If the grease cap on older models breaks off, the valve will leak air or water. Replace cap or use 1/8" plug.

Jandy Valves make pool system integrations easier. Many different configurations or layouts can be accomplished with Jandy and other 3-way valves. Take a look at some of these Jandy Valve Diagrams for Pool & Spa plumbing.