Pentair Rebel V2 Stays on Main Drain

When the Rebel V2 consistently returns to the main drain and sits there rather than cleaning the pool, the cause is almost always that the main drain is drawing suction while the cleaner is operating. The cleaner is pulled toward and held by the strongest suction point in the pool — and if the main drain is open, it is that point. The Pentair manual identifies two required conditions for this symptom: the main drain valve must be closed, and a proper drain grate must be installed and flush with the pool floor.

Required Fix 1: Close the Main Drain Valve

The Rebel V2 is a pressure-side cleaner, meaning it is driven by the pump's output pressure rather than suction from the return line. However, the pump still draws suction from the pool through available suction ports. If the main drain valve is open, the pump draws suction through the main drain simultaneously with the skimmer. The main drain sits at the lowest point of the pool floor, which means the cleaner — also operating near the floor — is pulled toward it by the suction differential.

1. Locate the main drain valve at the pool equipment pad — this is the valve on the suction side plumbing that controls flow from the main drain
2. Close the main drain valve completely by turning it to the fully closed position
3. The pump should now draw suction only from the skimmer(s) — suction is distributed away from the pool floor center
4. Return the cleaner to the pool and verify it no longer concentrates on the main drain area

Required Fix 2: Verify the Main Drain Grate Is Installed and Flush

The Pentair manual specifically states that the main drain grate must be installed and that the drain must be flush with the pool floor. A missing or improperly installed grate concentrates the remaining suction from around the drain fitting into a smaller open area, creating a localized suction point that can draw the cleaner even when the main drain valve contribution is reduced.

1. With the pump off, visually inspect the main drain at the bottom of the pool
2. Verify a grate cover is installed over the drain opening — a drain opening without a grate allows the cleaner body to be drawn directly onto the opening and held there by suction
3. Verify the grate sits flush with the pool floor surface — a grate that is recessed below the pool floor creates a depression that the cleaner can fall into and become trapped; a grate that protrudes above the floor creates an obstacle the cleaner climbs and cannot easily leave
4. If the grate is not flush with the pool floor, contact a pool professional to correct the drain cover installation — this is not an owner-serviceable adjustment in most pool types

Rebel V2 Troubleshooting Reference (from Manual)

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