RO Purifier Not Working? No Water, Slow Flow or Bad Taste - Fixes and Costs

An RO purifier is a chain of filters driven by a small pump, and when it stops working the fault is usually in one specific link. A few observations - is there any water, is it slow, has the taste changed - narrow it down quickly and stop you from replacing parts that were never the problem.

Before anything, check the obvious: is the unit getting power, and is the input water supply on? RO units switched off at a hidden socket, or fed from a dry overhead tank, account for a fair share of no-water calls.

No water from the purifier

If the tank is empty and nothing is flowing, and power and input supply are confirmed, the fault is electrical or in the valves. The SMPS adaptor (the power unit), the solenoid inlet valve, or the pump are the usual suspects. These are standard replacement parts in the 400 to 1,500 range with labour.

A unit that is silent when it should be pumping points to the adaptor or pump; one that hums but passes no water points to a blocked inlet or a choked pre-filter.

Tank fills too slowly

Slow filling almost always means the pre-filters or the RO membrane are choked with sediment and scale - the normal end-of-life of consumables. If your water is hard or silty, filters exhaust faster than the label suggests. A pre-filter and carbon set replacement is routine; a slow, tired membrane needs replacing too.

This is why an annual service exists: replacing consumables on schedule prevents the slow-flow and taste problems before they start.

Water tastes different or TDS has risen

If your purified water starts tasting salty, flat or off, the RO membrane is likely exhausted or water is bypassing it. The membrane is the heart of the system and the part that actually lowers TDS; when it degrades, dissolved salts pass through. A quick TDS-meter check before and after the unit confirms it.

A membrane replacement runs roughly 1,500 to 3,500 depending on capacity and brand. Insist on a genuine membrane - a cheap aftermarket one fails fast and undoes the saving.

It never switches off, or it leaks

A purifier that runs continuously and keeps draining has a faulty auto-off (the float switch or pressure switch that should stop it when the tank is full) - wasteful and a giveaway fault. Leaks are usually a cracked tube, a loose push-fit connector or a failed filter housing, all inexpensive.

Both are quick fixes, but a constantly-running unit also wastes a lot of water, so it is worth prioritising.

What to do next

Note whether you have no water, slow water, or changed taste, and match it to the table - it tells the technician which link in the chain to check and which genuine part to bring. Yantra4All offers a free water test and carries genuine membranes and filter sets on the visit, so most RO faults are closed the same day with the right parts, not guesswork.