When a tap starts to drip from the spout, it’s usually the washer that’s at fault. Replacement washers are available cheaply from hardware stores but, like the taps they fit, most are still in Imperial sizes — ¼ in. for basins, M in. for baths. Only imported Continental models and the more unusual modern designs are Metric, the equivalent sizes being 15mm for basins and 22mm for baths.
Tap washers seldom fail when the shops are open so it pays to dismantle one of each of your tap types while they are still in good order and take the washers to your local stockist so that spares can be matched up.
How To Change A Tap Washer
Start the job by isolating the water supply to the tap concerned.
Look for a stop valve on the pipe supplying the tap and turn this clockwise to cut off the water. If there are no such valves, what you do depends on whether the tap is for the hot or cold water supply.
If your plumbing system includes a cold storage cistern, look for a stop valve on the supply pipe running from the base. Otherwise tie up the ball valve to stop water entering the cistern, then open all your cold taps to drain it. (Note: this applies to bathroom cold taps: kitchen cold taps are plumbed direct to the rising main, in which case turn off the main stop valve to isolate them.) If you have a direct system with no cistern, simply shut off the main stop valve and open all the cold taps to drain the pipework.
Look for a stop valve on the cold supply pipe entering the base of your hot water cylinder or water heater. You may be surprised to find that this stops any hot water leaving the cylinder: simply open the tap being repaired, to drain any water still left in the supply pipe.
To get at the washer. Start by removing the tap handle. Oldstyle crutchtype handles are held on by a small screw —either under the colour button, or underneath the handle where it joins the tap stem. Follow by unscrewing the shroud below the handle with a pair of selfgrip pliers — put some cloth in the jaws of the pliers to protect the tap chrome.
1. Newstyle plastic handles either simply pull off or are held on by a screw fitted under the colour button.
2. The next step is to unscrew the entire stem assembly from the tap body. Get a spanner, selfgrip pliers or a plumber’s wrench around the large nut where the two meet and apply force. As you do so, take care not to move the tap body itself or you may disturb the pipe joint below. If the nut is tight, wedge the body with a length of wood against something solid so that you counteract the turning force. 3, 4. You will find the offending washer on the end of the stern unit. The older rubber sort arc held in a mounting plate by a small nut or screw. Undo this and dig out the washer, then slot in the new one, replace the nut and tighten.
Newer nylon washers simply snap into place on the end of the stem or onto a mounting plate —prise the old one off with the end of a screwdriver.
In both cases, reassembly is an exact reversal of the dismantling procedure.
TIP: If you do not have a replacement washer make a temporary repair by turning the old one round.
TIP: If your tap continues to drip, the washer seating is worn. The conventional solutions are to replace the tap or regrind the seat using a special tool. The easy way is to fit a ‘Hold-Tite’ domed washer or a push-in nylon seat — ask for thorn at your plumbing supplier.