Are you noticing a constant, heavy stream of water flowing out of your RO’s reject pipe, even long after the tank should be full?

It is completely normal for a Reverse Osmosis (RO) purifier to reject some water—usually about 3 liters for every 1 liter of pure water. However, if your RO is draining water continuously or rejecting far more than usual, it’s a clear sign that something inside the machine needs immediate attention. Ignoring this not only wastes hundreds of liters of water but can also permanently damage your purifier’s motor.
Here are the top three reasons your RO purifier is rejecting too much water, and what you can do about it.

1. A Choked or Blocked RO Membrane
The RO membrane is the heart of your water purifier. Over time, especially in areas across India with high TDS (Total Dissolved Solids) in the tap water, the microscopic pores of the membrane get clogged with dirt, calcium, and heavy metals. When the membrane is choked, pure water cannot pass through it efficiently, causing the system to send almost all the water out through the reject pipe.
The Fix: The RO membrane will likely need to be replaced.

2. Faulty Auto Shut-Off Valve (ASV)
Your RO machine has an Auto Shut-Off Valve that stops the water supply once the storage tank is full. If this valve becomes faulty or gets stuck, the machine doesn’t know the tank is full. As a result, water continues to flow through the filters and straight out of the reject pipe 24/7.
The Fix: Turn off the water supply to the RO immediately and have a technician replace the ASV.

3. Clogged Pre-Filters
Before water reaches the RO membrane, it passes through sediment and carbon pre-filters. If these filters are heavily blocked with mud or sand, the water pressure drops significantly. RO membranes require high pressure to function. Without it, the water simply washes over the membrane and goes down the drain.
The Fix: Regular servicing every 6 months to replace or clean the pre-filters.

When to Call an Expert?
While you can check the water pressure in your tap yourself, opening the RO cabinet to check the membrane or ASV requires technical expertise. Trying to fix it yourself without the right tools can lead to internal leaks or electrical issues.

Need a quick fix? At RO Sale & Services, our expert technicians can diagnose and repair your water purifier within 2 hours in over 100+ cities across India. We service all brands including Kent, Aquaguard, Pureit, and Livpure.

👉 Stop wasting water and protect your machine! Book a Repair Service Today starting at just ₹349, or Call/WhatsApp us at +91 7763003691.