A failing multiport valve — one that leaks at every position, won’t hold the handle in place, or sends water to waste even on the FILTER setting — is a job most pool owners can DIY. The whole valve assembly bolts on/off in 30 minutes once you understand the plumbing. This tutorial walks through replacing a top-mount or side-mount multiport valve.
When to replace the whole valve vs. parts
Replace just the spider gasket if water is bypassing internally. Replace just the handle and spring if the handle won’t hold position. Replace the whole valve when:
- The valve body itself is cracked.
- The threaded ports are stripped from over-tightening.
- The internal star key (rotor) has worn so badly that a new gasket won’t seal.
- The valve is 15+ years old and you’re overhauling the system anyway.
What you’ll need
- A new multiport valve of the same size (1.5″ or 2″) and configuration (top mount or side mount)
- PVC primer and cement (if the valve uses slip unions) OR Teflon thread tape (if threaded)
- Channel-lock pliers or a strap wrench
- New tank o-ring for the filter (if you’re also opening the filter housing)
- Silicone pool lubricant
Step-by-step
Pump off at the breaker. Open the air-relief on the filter. Open the drain plug. Let pressure drop to zero.
Most multiport valves have 2–3 threaded or slip unions: one to the pump (suction in), one to the filter, and one to the return-side plumbing (or waste line). Hand-loosen unions, or use channel-lock pliers with a soft cloth to protect threads.
For top-mount filters, the valve sits on a standpipe with an o-ring. Lift straight up. For side-mount filters, the valve is bolted to a flanged port; remove the perimeter bolts.
For top-mount: cover the now-exposed standpipe with a plastic bag taped on, so nothing falls into the filter laterals while the valve is off.
Before installing: verify the new valve has the same port sizes, the same port orientation (filter, pool, waste positions match), and the same connector type (threaded vs. slip). A mismatch means returning the part.
For top-mount: drop straight down onto the standpipe. Confirm the standpipe o-ring is seated. For side-mount: align bolt holes and tighten perimeter bolts in a star pattern. Replace the o-ring between the valve and filter port — always replace.
Hand-tighten unions first, then 1/4 turn with the wrench. Use Teflon tape on threaded connections. Confirm each union seats flat.
Push handle down, rotate to Filter, let it click. Close the air-relief partially.
Power on the pump. Watch every union and around the base of the valve for drips. Cycle through Backwash, Rinse, Waste, Recirculate, and back to Filter to verify each position works.
Multiport valves and parts in stock
Hayward SP0714T Top-Mount Multiport
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Pentair Praher TM-12-L Multiport
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Multiport Spider Gasket
Shop NowIf you’re unsure whether the valve itself needs replacement or just a spider gasket, see our spider gasket tutorial. The gasket alone is the right fix for 80% of multiport leaks.