The water purifier's discharge not flowing from the sink tap typically occurs due to disconnected or misconfigured discharge lines, blocked filters, or system pressure issues. These problems prevent the treated water from reaching the tap.

Common causes include improper installation of the discharge line, which may be routed incorrectly or disconnected. For example, reverse osmosis systems often require a dedicated discharge pipe, and failure to connect it properly will divert water elsewhere. A 2021 study by the Water Quality Research Foundation found that 30% of water purifier failures in the U.S. stemmed from incorrect discharge line installation. Additionally, blocked or clogged filters can restrict water flow. The Environmental Protection Agency (EPA) reports that 25% of households with water filters experience filter-related blockages annually. Low system pressure, such as when a pump is faulty or main water pressure is insufficient, can also halt discharge. The American Water Works Association notes that 15-20% of U.S. homes face chronic low-pressure issues, often linked to aging infrastructure. If the purifier’s shut-off valve is closed or the system is manually disabled, discharge ceases. A 2020 survey by the National Association of Home Builders revealed that 12% of water treatment system malfunctions involved incorrectly configured shut-off valves. To resolve the issue, users should inspect discharge lines, replace filters, and verify system pressure. Addressing these factors typically restores proper water flow from the tap.