How to Fix a Dripping Tap in a CPVC Plumbing System

Quick answer: Close the isolating ball valve under the basin by turning it 90 degrees, then open the tap to release pressure. On a washer-type tap, remove the handle and spindle and replace the worn washer at its base; on a single-lever tap, replace the whole ceramic disc cartridge, which is brand-specific. If the leak is at the pipe connection instead, re-seal the male thread with 2 to 3 wraps of PTFE tape.

A dripping tap is one of the most common household plumbing complaints in Bengaluru homes. Beyond being irritating, a tap that drips at one drop per second wastes roughly 10,000 litres of water per year, a meaningful amount when Bengaluru faces seasonal water supply shortages. The good news is that most dripping tap problems can be fixed in under an hour without specialist plumbing skills, provided you have the right replacement part.

This guide covers the most common scenarios in a home with CPVC supply pipes, which is the standard in most apartments and houses built in Bengaluru over the last fifteen years.

Identify the type of tap you have

Before you start, identify which type of tap mechanism you are dealing with. There are two main types in Indian residential use:

Washer-type taps (also called compression taps) have a rubber or synthetic washer at the bottom of the spindle that presses against a valve seat to stop the flow. These taps require multiple turns to open and close. When a washer wears out, the tap drips or fails to fully shut off. Washer replacement is a simple and inexpensive repair.

Ceramic disc cartridge taps use a pair of ceramic discs that rotate against each other to control flow. These are the single-lever taps common in modern kitchens and bathrooms. They turn 90 degrees to open fully and are generally more durable than washer taps. When a ceramic disc tap drips, the cartridge itself usually needs replacement rather than repair.

In a Bengaluru apartment built in the last decade, kitchen taps are often single-lever ceramic disc taps, while some bathroom basin and bath taps use the older washer mechanism, particularly in budget-specification buildings.

Turn off the water supply before you start

This step is essential. Before opening a tap, shut off the water supply to that tap. In a well-installed CPVC system, there should be an isolating ball valve on the supply line under the basin or behind the kitchen unit. Turn this valve 90 degrees to close it: the lever should be perpendicular to the pipe when closed.

If there is no isolating valve on that line, you will need to shut off at the bathroom main supply valve, or if there is no bathroom valve, at the apartment main stop valve, which is usually located near the meter or at the main supply riser. This is one reason why isolating valves on every supply line are worth insisting on during plumbing installation: they allow individual fixtures to be isolated without shutting down water to the whole apartment.

After closing the valve, open the tap to release any pressure and residual water in the line. Place a small towel or container under the tap mechanism before you start disassembly to catch drips.

Replacing a worn washer

For a washer-type tap, the repair involves removing the spindle and replacing the washer at its base. The process is as follows:

First, remove any decorative cap on the tap handle. This is usually a small plastic disc that pops off with a flat screwdriver, revealing a screw underneath. Remove the screw and pull off the handle. Below the handle you will find a packing nut or gland nut. Use an adjustable spanner to loosen and remove this nut (turn anticlockwise). With the nut removed, the spindle can be pulled out of the tap body.

At the bottom of the spindle you will see the washer, a small rubber or synthetic disc held by a small brass screw. The washer is often visibly worn, cracked, or deformed. Undo the brass screw, remove the old washer, and fit a replacement of the same size. Washers are sold at most hardware stores and pipe dealers in standard sizes. If you are not sure of the size, take the old washer with you when you buy.

Reassemble in reverse order: screw the new washer to the spindle, insert the spindle into the tap body, tighten the packing nut, refit the handle and screw, and replace the decorative cap. Slowly reopen the supply valve and check for drips. The tap should now close fully with a firm turn.

Replacing a ceramic disc cartridge

For a single-lever ceramic disc tap, the repair involves replacing the entire cartridge rather than a single part. Cartridges are brand-specific, so you will need to identify the tap brand or take the old cartridge to a plumbing hardware shop to find the correct replacement.

With the supply off and the tap open to release pressure, look for a decorative cap on the lever handle, often a small round cap that conceals a screw. Remove the screw and lift off the handle. Below the handle is the cartridge, usually held in the tap body by a retaining nut or clip. Unscrew or release this retaining mechanism and pull the cartridge straight out of the tap body.

Take the old cartridge to a plumbing supplies shop or search online using the tap brand name and the cartridge dimensions. Common cartridge sizes in Indian taps are 35mm and 40mm diameter. Fit the new cartridge, aligning any keyway or flat with the corresponding feature in the tap body, and reassemble. Reopen the supply and test the tap.

If the replacement cartridge is the correct type and has been fitted correctly, the tap will operate smoothly with no drip when closed. If it still drips slightly after fitting, the ceramic discs may not have seated fully. Open and close the tap a few times with the water on to allow the discs to find their position.

When the tap body itself is the problem

Occasionally, the tap body has corroded or cracked at the connection point, and no washer or cartridge replacement will solve the drip. In CPVC plumbing systems, the tap connects to the CPVC pipe via a threaded adapter: either a female threaded inlet on the tap connecting to a male threaded CPVC fitting, or a direct push-fit connection depending on the installation.

If the leak is coming from the pipe connection rather than from inside the tap, the first thing to check is whether the thread has been sealed with PTFE tape (thread seal tape). CPVC threaded connections to tap inlets should have PTFE tape on the male thread. If the joint was installed without tape or the tape has degraded, the joint can be disassembled and re-taped. Use 2 to 3 wraps of PTFE tape clockwise around the male thread before reassembling.

If the tap body itself is cracked or the thread is stripped, the tap needs to be replaced. Replacing a tap in a CPVC system requires cutting the supply pipe back to a sound section, fitting a new CPVC male thread adapter using CPVC solvent cement, and threading the new tap inlet onto the adapter with PTFE tape. This repair is more involved than a washer or cartridge replacement and may be worth calling a plumber if you are not comfortable working with solvent cement joints.

Preventive maintenance to reduce drips

Most tap failures are gradual: the washer wears slowly, or the ceramic disc develops a micro-crack over time. A few practices extend tap life and reduce the frequency of repairs.

Do not overtighten taps when closing. Forcing a tap shut puts excess pressure on the washer or ceramic discs. The tap is closed when the drip stops; pushing further damages the seat and accelerates wear.

If your building water pressure is higher than normal (which happens when apartments in Bengaluru are connected to overhead tanks at significant height), a pressure-reducing valve on the main supply into the apartment is worthwhile. High water pressure accelerates washer wear and also stresses CPVC joints over time.

If you are unsure about the quality of your current taps and your building is more than ten years old, an inspection by a competent plumber every few years can identify worn washers and cartridges before they cause water damage or visible drips.

For replacement tap fittings, CPVC adapters, or any pipe and fitting supplies in Bengaluru, AR Trading Company stocks a range of fittings at our Viveknagar counter. WhatsApp us or use our online quote tool if you need to check availability before making the trip.

If the drip turned out to be a wrong material rather than a worn washer, which happens more often than people expect on hot lines, read CPVC against uPVC before you buy the replacement pipe.