A water filter leaking from the top usually means the O‑ring or gasket in the filter head isn’t sealing. The most common cause is a dry, pinched, or misplaced O‑ring after a recent cartridge change, which lets pressurized water escape. Our plumbers see this often in Central Indiana homes and can service, maintain, or repair any brand of purifier or reverse osmosis system. Other causes include a cross‑threaded sump, an over‑tightened housing deforming the seal, a cracked head or bowl, or high inlet pressure driving water past an otherwise good seal. A flattened O‑ring can look fine but won’t hold pressure once flow starts.
Try these quick checks:
- Turn off water and depressurize the housing before opening.
- Remove, clean the groove, and lubricate the O‑ring with food‑grade silicone.
- Reseat the cartridge; hand‑tighten the housing evenly without tools.
- Inspect the head and bowl for hairline cracks or leaking fittings.
If the leak continues after reseating and lubricating the O‑ring, shut off the feed and call a licensed plumber.
Updated: 2026-09-30
Need help in Fishers, IN? Call 317-830-5862 or book online. “It was a pleasure to welcome Jade into our home to install a new water softener and a new RO filter.” — Lawrence G.