Tools and materials
The tools and materials you need to change a washer are available from hardware or plumbing supply stores. You will require: adjustable spanner to fit tap nut Valve or tap washer Body washer O-ring Silicon lubricant or Vaseline Needle nose pliers
1. Turn off the water mains: this stops all water flowing into your house. The tap & water meter for homes will probably be out on the street or in your front yard adjacent to the street. If you live in a flat or townhouse the mains tap will probably be inside, for example in the bathroom or a cupboard. Turn on a tap in or around the house to make sure that the water has ceased to run. (If the water has not stopped running, it will be necessary to call a professional plumber). If the mains tap has not been used for many years, you may need a pair of multigrips to help turn it off. Ensure you need to know where the mains tap is to be able to turn the water off in an emergency. If you are not sure where it is, even if you don’t need to change a washer, find out now!
2. Undo the head nut: once the mains water has been turned off, undo the head nut on the leaking tap.
3. Replace the washers: you could just replace the tap washer, but it is a good idea to replace all three washers at the same time. These are: The large washer around the head nut, which is called the body washer (usually orange in colour). It should lift off quite easily. The O-ring on the spindle. To change the O-ring, you need to fully close the tap until the O-ring appears. Then, with a pair of needle nose pliers (or a screwdriver or a sharp knife), prise or cut it off. The new O-ring should easily stretch and roll on to the spindle.
Lastly, replace the tap washer. It may simply slide out of the spindle or stay sitting in the body of the tap, in which case you will need a pair of small pliers to remove the washer.
4. Reassemble: first ensure the spindle and the threaded areas are lubricated with a silicon lubricant or Vaseline.
5. Turn the mains back on: once the tap is reassembled, open it half way and then turn on the mains. When turning the tap off after the washer has been replaced, use gentle finger pressure. Over-tightening will cause a lot of damage to the tap seat. A tap should only be tightened until the water flow stops, no further. (Note: If the tap is still leaking after you have replaced the washer, it means the seat is “pitted” and you will need a plumber to regrind the seat for you.
Most of inside taps take 12mm (1/2″) washers; while outside taps (garden taps) take 3/4″ (18mm). Washers cost around $2.00 to $3.00 each. The most popular washer (used by most plumbers) is a heavy-duty washer suitable for hot and cold taps, with a copper base and a yellow top (Delaware valve) – approximately $3.00 each. This same type of washer is good for outside garden taps – 18mm costs approximately $3.00 each.
If your taps are very old, take the worn-out washer to the hardware or plumbers’ supply store so that you get the right washer for your tap.