Answer: The single most common cause (40-50% of cases) is storage tank valve accidentally closed. This happens during cleaning, filter changes, or when someone mistakenly turns the valve thinking it's something else. How to check: Locate the valve on your storage tank (usually on top or side where tube connects). The handle should be parallel to the tube for "open" position. If it's perpendicular (90 degrees) to the tube, it's closed. Simply turn it parallel and water should flow immediately. Second most common: Inlet water supply valve closed under sink (25-30% of cases). Check both before trying complex troubleshooting.

Answer: This is almost certainly an airlock - air trapped in the system when you opened filter housings. When housings are opened, air enters the system and prevents water from flowing properly. Solution: You need to bleed the air out. Method: (1) Turn off power; (2) Disconnect the tube going INTO the storage tank; (3) Place bucket underneath; (4) Turn power back on and let pump run for 2-3 minutes until water flows steadily without air bubbles/sputtering; (5) Reconnect tube to tank; (6) System should work normally now. Prevention: Always bleed air after ANY filter replacement. Some technicians skip this step, causing "no water" problems. Also check if filter housings are tightened properly - loose housings can suck air.

Answer: Listen carefully to the pump sound: Normal working pump: Steady humming/vibrating sound. If you hear this but no water, the problem is NOT the pump - it's blocked supply, closed valves, or airlock. Failed pump indicators: (1) High-pitched whining or screaming sound = pump running dry without inlet water OR pump impeller damaged; (2) No sound at all even when powered = electrical failure or motor burnout; (3) Clicking/stuttering sound = pump trying to start but failing. Simple test: Disconnect inlet tube to pump and check if water flows from your supply when valve is open. If yes (water available) but pump still whines/fails = pump problem. If no water from inlet = supply problem, not pump. Warning: Never run pump continuously (>5 minutes) with high-pitched whining - this damages pump permanently.

Answer: Sudden overnight "no water" is usually NOT a filter clogging issue (that happens gradually). Most likely causes: (1) Building water supply cut off - check if regular taps work. Municipal cuts, tank empty, or building maintenance can stop supply. (2) Someone closed a valve - during cleaning, someone may have accidentally turned inlet or tank valve. (3) Tube popped out - vibration or movement can dislodge a push-fit tube connection, especially if it wasn't fully seated. Check for water pooling under sink. (4) Auto shut-off valve stuck - can suddenly jam in closed position due to sediment or mineral buildup. (5) Power supply issue - if RO is plugged into a switched outlet, check if power is reaching it. Diagnosis approach: Start with simplest (check valves, check water supply, check power) before assuming component failure.

Answer: If reject water is flowing strongly to drain but you get zero purified water from the tap, this indicates the problem is AFTER the RO membrane, not before it. Water is entering the system and going through membrane (hence reject flow), but purified water path is blocked. Most likely causes: (1) Tank valve closed - check storage tank valve position (most common). (2) Auto shut-off valve stuck closed - valve that stops tank filling when full is jammed. Try tapping valve body gently. (3) Tube disconnected between membrane and tank - purified water leaking somewhere instead of going to tank. Check for leaks. (4) Post-carbon filter completely clogged - rare but possible. (5) Tank-to-tap tube disconnected or crimped. Quick test: Disconnect tube from tank output and see if purified water flows when pump runs. If yes = tank valve or tube problem. If no = membrane-to-tank blockage.

Answer: Critical safety limits: If pump is running with high-pitched whining (dry running, no inlet water): Turn off immediately - even 5 minutes can cause damage. Dry running generates extreme heat and friction, burning out pump motor and seals. If pump sounds normal (steady hum) but no output: Maximum 20-30 minutes before turning off to prevent overheating. The pump is working against resistance (blockage or closed valve), which stresses the motor. What happens with extended running: (1) Motor overheating → coil burnout (₹2,000-₹4,000 replacement); (2) Seal damage → leaks (₹800-₹1,500 repair); (3) Impeller wear → reduced performance permanently. Best practice: If you hear pump running but get no water, diagnose the issue within 10 minutes and turn off power while troubleshooting. RO pumps are designed for intermittent operation (15-20 min cycles), not continuous running.

Answer: Not recommended for regular use, but possible as emergency temporary measure. What auto shut-off valve does: Automatically stops tank filling when full (senses back-pressure). Prevents continuous water wastage to drain. Bypass method (emergency only): Disconnect the tube that goes to the pressure sensor (usually one of 3-4 tubes on valve body - trace it to tank). This removes pressure feedback, making valve think tank is always empty, so it stays open. Risks of bypassing: (1) RO will run continuously and waste water to drain even when tank is full; (2) High water bill from constant reject water; (3) Pump runs unnecessarily, shortening its life; (4) Tank can overfill if pressure builds up. Better solution: If auto shut-off valve is stuck, professional replacement costs only ₹300-₹800 and takes 30-45 minutes. Much safer than bypass. Use bypass ONLY for emergency water access until technician arrives (maximum 1-2 days), and monitor system closely.

Answer: For brand new installations, it's normal to wait 1-3 hours before getting first water from tap, but you should see certain signs that system is working: Normal installation behavior: (1) Pump runs intermittently (15-20 min on, then off when tank pressure builds); (2) Water flows to drain (reject water) within 5-10 minutes of starting; (3) You can hear water filling inside tank (if you put ear near tank); (4) After 1-3 hours, tap should dispense water. Problem indicators: (1) Pump runs continuously without stopping (auto shut-off issue); (2) NO water to drain even after 30 min (no inlet supply or airlock); (3) Water to drain but pump never stops (tank not filling - disconnected tube or valve issue); (4) After 4+ hours still no water from tap (definite problem). What to check: Verify installer opened all valves (inlet, tank), bled air from system, and connected all tubes properly. Many "new installation no water" issues are due to skipped steps during installation. Call installer back if no water after 4 hours.