How to match a pool valve
Match a pool valve by the job it does, then by port count, pipe size, and whether the ends are slip, threaded, or union. A ball valve, a check valve, a diverter, and a multiport are not substitutes.
· 6 min read
Name the job first
A ball valve opens and closes a line. The handle in line with the pipe is open. The handle across the pipe is closed. A check valve lets water one way, and the arrow on the body is that direction. A diverter sends water to one port or another, as on a pool and spa line. A multiport sits on a sand or DE filter and has positions such as filter, backwash, and rinse.
Those four are not substitutes. A check valve will not shut the line off for service. A ball valve will not stop water from flowing backward. Order the type you removed.
Count the ports and measure the pipe
Pool plumbing is commonly 1.5 inch or 2 inch. Slip ends glue onto pipe. Threaded ends screw on. A union end comes apart. The same rules are in how to match a replacement part.
On a diverter, note whether it is two-way or three-way, and which port was the inlet. Photograph the handle position before you pull the valve so the new one can go back in the same orientation.
Multiport valves
A multiport is matched to the filter brand, the filter model, and the plumbing size on the valve body. Turn the pump off before you move the handle. Moving it while the pump is running can break the spider gasket. Backwash steps are in how to clean a pool filter.
Ball valves, check valves, and diverters are in plumbing. Multiports that belong to a filter are with the filters in equipment.
Questions
What is the difference between a ball valve and a check valve?
A ball valve opens and closes the line. A check valve lets water pass in one direction only, the way the arrow points. They are not interchangeable.
How do I know if a pool valve is 1.5 inch or 2 inch?
Read the size molded into the valve body, or measure the pipe it is glued to. Also note slip, threaded, or union ends. The two pipe sizes are not interchangeable without an adapter you meant to buy.
Can I turn a multiport valve while the pump is on?
No. Turn the pump off, move the handle, then start the pump in the position the valve manual allows. Turning it under pressure can break the spider gasket.