The principle behind a faucet is simple: turn it on — Water flows; flip it off — Water stops flowing. That simple concept has led to the development of four distinct kinds of faucet valves, each with its own idiosyncratic method of regulating water circulation. Any kind of faucet may leak, but it’s rare for one to stop functioning altogether. When that happens, the wise plumber suspects the water system.
Faucet Design
A faucet is essentially a shutoff valve. The valve stem seals against the Water inlet to hold water back when the faucet is closed and releases the seal when you turn the faucet on. A traditional compression valve screws down onto the valve seat if you flip the handle through repeated rotations. Other faucet designs depend on springs, washers, notched balls, cartridges or interlocking discs to regulate water flow. If there’s pressurized water in the pipes, then there’s little a faucet can do to prevent it from flowing if you turn its handle and open the seal.
Isolating the Problem
It’s a good idea to confirm the water source before you consider replacing a faucet that isn’t running, and also the best place to start is below the sink. Both shutoff valves should be on all of the way. If they are — and the faucet still isn’t functioning — flip them off, disconnect the supply hoses from the faucet and point them into a bucket. If you find yourself with a strong flow when you flip on the valves, then the fault is at the faucet. If there’s no flow, there could be an issue in the pipes or in the water resource.
Possible Causes of Low Pressure
You may have low pressure in the faucet because a valve is partially closed somewhere else at the home, perhaps because someone was doing plumbing fixes. The low pressure might also be the consequence of mineral deposits in the pipes. If the absence of pressure is mainly in the warm water faucet, deposits in the water heater might be blocking the warm water outlet. A more troublesome cause of low water pressure is a burst or leaking pipe. Should you suspect one, start looking for soggy places in the yard or water running along the ground to pinpoint it.
Faucet Malfunctions
If there’s plenty of water pressure, the faucet itself might have become clogged by mineral deposits. The spout aerator is a likely place for deposits to collect, and if that is what has occurred, the faucet should run normally when you remove it. You can clean it by soaking it overnight in vinegar. The notches at a ball- or cartridge-style valve may also become blocked by minerals, and also you can usually chip those away with a flathead screwdriver after removing the valve from the faucet. Finally, check the temperature controller in your single-handle faucet and be sure it isn’t preventing you from turning the handle far enough to open the valve.