Taps fall into three main design categories, wall mounted taps are known as Bib Taps, those mounted directly onto the sink, basin or bath are called Pillar Taps, and finally there are Mixer Taps, which have a hot and cold valve linked to a single spout. By law, mains and stored water (hot water from your storage tank) cannot be mixed in a system. This means that all sinks have separate pipes to isolate hot from cold.
Traditionally, almost all taps used the Pillar design. These work by having a Rubber or Nylon (or leather) washer on a threaded pillar inside the body of the tap. When the tap was closed, the washer would sit on top of the water supply pipe. As the tap is unscrewed the whole pillar unscrews and rises with the washer, allowing the water to pass into the spout. Modern taps most often use a non-rising head. This means that while they work in almost the same way, the threaded pillar and washer rise without turning, reducing wear on the washer. The washers themselves have also evolved, with many modern taps (usually the more expensive brands) using precision ground ceramic discs. These have the advantage of very little wear and also do not suffer from limescale build up.
Leaking Taps
The most common problem with taps is leaking or dripping. A leaking cold tap is not much more than a nuisance, but a leaking hot tap, if left, can cost you money. The weak point in any rising spindle or non-rising taps is the washer. A sure sign that the washer needs replacing is water leaking from the spout. You can buy a specific hot or cold replacement washer, or a universal washer, for a few pence. If the water is leaking from top of the tap head when you turn it on, the O-ring or gland packing is at fault. Both jobs are very easy.
Repairing Bib and Pillar Taps
Firstly, put the plug in the sink or bathtub you are working on and lay a towel in the bottom of it. If you drop any small screws or nuts, they then won't be lost in the waste pipe. Now turn off the water supply (usually a small screw on the pipe below the tap) and drain the head of the pipe. Once no more water comes out, open the tap as far as possible. If your tap is an old pillar style, unscrew the shroud (dome at the top) by hand to reveal the Head Gear Nut. Carefully unscrew this and lift the whole mechanism out. The washer is located at the bottom of the Head Gear. Check the washer to see if it corroded or split. If it is, remove and replace it. Then carefully reassemble the tap and turn the water back on. If the washer looks sound, check the Seat (the bit inside the body of the tap that the washer would sit on). If there are grooves in the Seat, you can buy Seat Grinders to smooth them out. These are fairly cheap and a useful tool to have in your DIY kit.
Repairing a Reverse Pressure Tap
Reverse pressure taps are upside down when compared to normal pillar taps. The washer is screwed upwards onto the seat rather than downwards. Reverse Pressure taps have an integral check valve i...
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