How to Position a Multiport Valve for Winter Storage

We often forget that a multiport valve has its own winter storage needs because most of the attention during pool closing goes to the pump, filter, heater, and plumbing. Yet leaving the valve in the wrong position can keep the internal diverter compressed against its gasket, trap water where you do not want it, or make proper drainage more difficult. The correct storage position depends on the valve design, so the safest approach is to understand what the winter setting is actually doing rather than simply leaving the handle wherever it happened to be when the pool was closed.

On many common multiport valves, the proper winter position either has a dedicated WINTER or WINTERIZE marking or places the handle between normal operating detents. Both approaches are intended to relieve pressure on the internal valve seal and help leave drainage paths open. Your valve manufacturer's instructions should take priority because multiport valve designs are not completely interchangeable.

Why the Valve Should Not Simply Stay on Filter

During swimming season, the FILTER position is exactly where the valve belongs most of the time. Internally, however, the diverter is pressed firmly against a rubber seal often called a spider gasket. That pressure helps route water through the correct ports while the pump is running.

Leaving the valve fully locked into a normal operating position throughout a long shutdown can keep the diverter spring compressed against that gasket for months. A proper winter setting is designed to remove or reduce that pressure. Some manufacturers specifically instruct owners to use the winter position so the diverter does not remain loaded against the seal during storage.

The winter position can also leave multiple internal passages open. That matters in freezing climates because trapped water inside the valve needs room to drain and, if a small amount remains, room to expand rather than being confined inside a closed passage.

Dedicated Winter Position vs. Between-the-Notches Storage

Pool owners sometimes hear conflicting advice about whether the handle should point to WINTER or sit between two settings. Both instructions can be correct for different equipment.

Some six-way valves include an actual WINTER or WINTERIZE position. When selected, the valve is intentionally configured for seasonal shutdown. Other valves accomplish the same general purpose by having you press the handle down, rotate it away from the normal detents, and gently release it with the pointer positioned between two settings.

That between-position technique is not the same as choosing a random operating position. The idea is to prevent the diverter from seating tightly into one set of ports while allowing the valve to remain open enough for drainage.

Do not assume that every valve can safely be stored between detents. If your valve has a clearly labeled winter setting, that is generally the position to use unless its manual specifies otherwise.

A Practical Winter Storage Sequence

Valve positioning should be one of the final steps in winterizing, not the first. A typical sequence looks like this:

1. Turn the circulation pump off completely.
2. Backwash or clean the filter if required by the filter manufacturer's closing procedure.
3. Relieve filter pressure and verify that the pressure gauge reads zero before opening drain plugs or servicing equipment.
4. Drain the pump, filter, heater, chlorinator, and other equipment according to their individual instructions.
5. Clear or protect the plumbing as required for your climate and pool configuration.
6. Remove the appropriate drain plugs and store them as recommended.
7. Position the multiport valve in its designated WINTER/WINTERIZE position, or use the manufacturer's specified between-detent position.

A multiport valve should never be rotated while the pump is running. Changing positions under flow can damage the valve gasket and send water in unintended directions.

Do Not Use CLOSED as a Winter Storage Shortcut

CLOSED may seem like the most protective setting because nothing can flow through the valve, but that is usually the opposite of what you want for freeze protection. The CLOSED position blocks the valve passages. If water remains trapped inside the valve or connected plumbing, it has less opportunity to drain.

CLOSED also creates a serious startup hazard. If someone accidentally energizes the pump while the valve is closed, pressure can build rapidly because the pump has nowhere to send water. A closed valve is an operating position for specific service situations, not a general winter storage setting unless your equipment manufacturer explicitly says otherwise.

What About Backwash, Rinse, Waste, or Recirculate?

These settings are designed to direct water through particular routes while the system is operating. They are useful during cleaning, lowering the water level, bypassing the filter, or maintaining the filter, but none should automatically be treated as a substitute for the manufacturer's winter position.

For example, WASTE may open a route to the waste line while still seating the diverter against other ports. RECIRCULATE bypasses the filter but remains a defined operating position. BACKWASH and RINSE also direct water through specific pathways. A winter setting is different because its purpose is seasonal storage rather than circulation.

One Detail Pool Owners Often Miss: The Waste Line

If your multiport valve connects to a hard-plumbed waste line, make sure that line is included in the winterizing process. Water can remain in a long waste pipe even when the filter tank itself has drained.

This becomes especially important when the waste line runs outdoors, underground, or through an area exposed to freezing temperatures. The valve can be positioned perfectly while water remains trapped farther downstream. Winterizing the valve and winterizing every connected pipe are related but separate tasks.

The Filter Still Has to Be Drained

Moving the valve handle to WINTER does not magically drain a sand or DE filter. Drain plugs still need to be removed or opened according to the manufacturer's procedure. Some filter tanks drain slowly, so sufficient time should be allowed for water to leave the vessel.

Likewise, the pump strainer housing, heater headers, booster pumps, chemical feeders, water features, and other equipment may have their own low points. Pools with attached spas can have even more plumbing branches that require attention.

Should You Push the Handle Down All Winter?

Usually, no. Depressing the handle is commonly required while rotating the valve, but the manufacturer's prescribed winter position should determine how the handle rests afterward. On valves designed to sit between detents for winter, the handle may remain slightly elevated or disengaged from the normal locking positions once released.

Do not strap the handle down, wedge it in place, or improvise additional spring pressure. The goal is generally to reduce stress on the internal sealing surfaces, not increase it.

If the Handle Is Hard to Move During Closing

A stubborn multiport valve deserves attention before winter rather than brute force. Sand or debris can sometimes interfere with the diverter, while an aging gasket, worn spring, damaged key assembly, or internal swelling can make movement difficult.

Confirm that the pump is off and system pressure has been relieved before attempting to reposition it. If the handle still requires excessive force, servicing the valve may be safer than forcing it and breaking the handle or internal assembly.

When Spring Arrives

Before restarting the pool, reinstall the required drain plugs, return the multiport valve to the proper operating position, open any valves that were closed for winterization, and confirm that the system is ready to hold water. Start the pump only after the equipment has been correctly reassembled and the valve is positioned for normal operation.

Watch the valve and filter closely during initial startup. Drips around the valve body, waste-line leakage while set to FILTER, or water appearing where it should not can indicate a sealing problem that developed or became noticeable during storage.

A Separate Pool-Owner Check Worth Keeping in Your Toolkit

Winterizing the multiport valve is about protecting equipment, not diagnosing water loss. Once the pool is operating again, however, unexplained water-level changes may deserve their own investigation. A Mini Bucket Test can serve as a simple first step to help compare normal evaporation with possible leak-related water loss. It does not identify where a leak is located or replace professional leak detection when that is needed.

Bottom Line

For winter storage, a multiport valve should normally be placed in the valve manufacturer's dedicated WINTER or WINTERIZE position. If the valve has no dedicated setting, its instructions may call for storing the handle between normal detents so internal passages stay open and pressure is relieved from the gasket. The important part is not the label alone. The valve should be fully depressurized, properly drained, and stored exactly as its design requires. Taking a few extra minutes to position it correctly can help protect one of the hardest-working pieces of your pool's circulation system through the entire off-season.