Polaris Polaris 3900 Sport Pressure-Side Pool Cleaner MECH-TAIL-SWEEP Error Fix: Tail Sweep Not Working or Broken

Error code MECH-TAIL-SWEEP on the Polaris Polaris 3900 Sport Pressure-Side Pool Cleaner means: Tail Sweep Not Working or Broken. The tail sweep (the long flexible tail or "sweep hose" trailing behind the cleaner) is not sweeping debris into the filter bag, or it has broken off. The tail sweep is designed to stir up fine debris so the cleaner bag can capture it: (1) Tail sweep is cracked or broken — replace the sweep hose. These wear out over time from UV exposure and pool chemicals. (2) Tail sweep arc is too short — the sweep should reach about 2/3 of the way across the cleaner. If it is too short, it is worn and needs replacement. (3) Tail sweep scrubber (the small disc on the end) is missing or worn — replace it. (4) The water supply to the tail sweep is blocked — check the internal tubing connection inside the cleaner body. (5) On some models, a tail sweep wear ring keeps the tail from dragging; replace if worn.

The most successful fix is "Inspect and Repair Internal Tubing and Tail Sweep Wear Ring" (medium difficulty, ~45 minutes). Estimated DIY cost: $15-$20. HomeMD has 2 community-ranked fixes for this error.

This error is rated info severity. It is generally not urgent and can often be resolved with a simple DIY fix.

Yes — the top-ranked community fix ("Inspect and Repair Internal Tubing and Tail Sweep Wear Ring") is rated medium difficulty and takes about 45 minutes. Tools needed: T15 Torx screwdriver, Scissors, Flashlight.

DIY cost: $15-$20. Professional repair typically costs $120-$180. Many homeowners save money by trying the top-ranked community fix first.

The Polaris Polaris 3900 Sport Pressure-Side Pool Cleaner has 8 other known error codes, including: MECH-BACKUP-VALVE (Backup Valve Not Cycling), MECH-BELT (Drive Belt Broken or Worn), MECH-CLIMBS-FLIPS (Cleaner Climbs Wall and Flips Over), MECH-FILTER-BAG (Filter Bag Issues — Torn, Falls Off, or Fills Quickly), MECH-HOSE-FLOAT (Hose Float Issues — Sinking or Wrong Position), and 3 more.

Error code MECH-TAIL-SWEEP also appears on 3 other Polaris models: Polaris 280 Pressure-Side Pool Cleaner, Polaris 360 Pressure-Side Pool Cleaner, Polaris 380 Pressure-Side Pool Cleaner. The fix may vary by model, so check each model's specific page for tailored repair steps.