- Is it OK to substitute stems?
As a general rule each stem has a unique set of diameters, thread pitches and lengths. A different stem will not fit (and if it does, it will not function properly). There are certain instances where the same stem has been produced in different lengths and these may be substituted. Also, in many cases the Hot and Cold versions of the same stem may be interchanged (although this can cause confusion and possibly scalding).
- What is the difference between a Hot stem and a Cold stem?
Hot and Cold stems are essentially the same except that they turn opposite directions to shut off. Most Hot stems turn to the LEFT (counter-clockwise) to close and most Cold stems turn to the RIGHT (clockwise) to close. When the shape of the faucet handle is round, square or cross, both the Hot and Cold stems normally turn in the same direction. Usually, when you look at the threads on the stem, the direction they slant is the side of the faucet they belong on.
Some stems have an indication of which side they belong on imprinted on them. In some cases the mark indicates the direction they turn to close, RH (right hand - generally Hot) or LH (left hand - generally Cold). In other cases the indication is a notch on the stem gland. The code is no notch = Hot, one notch = Cold, two notches = use for both HOT and COLD.
- Can you repair a Ceramic cartridge?
Most Ceramic cartridges are truly "washerless", which means when they leak you toss them out and put in a new one. Many Ceramic cartridges have a gasket on the bottom to seal between the cartridge and the base of the faucet. Normally there is no wear on this seal and replacing it will not fix the leak.
- What if you change the stem and the faucet still leaks?
Certain washerless 2-handle faucets use a washer (they call it a seat or a seal) and sometimes a spring below the stem to shut off the water. Most often the faucet leaks because debris in the water becomes caught between this washer and the stem and damages the washer. Often just replacing the washer will fix the leak.
Compression faucets shut off by jamming the washer (on the bottom of the stem) against a seat (in the base of the faucet). Generally, if you replace the stem and the faucet still leaks it indicates that there is a problem with the seat. Most faucets have seats that are removable.
- How do you remove a seat?
You can tell if a seat is removable by looking at the bottom surface of the inside of the faucet where you removed the stem. The seat is the raised surface surrounding the inlet hole. If the hole in the seat is square or hexagonal or if there is a slot, then it is removable.
To remove the seat you usually need a seat wrench. The most popular style of seat wrench is an inexpensive "L-shaped" bar. One end of the bar is square shaped and the other end is hexagonal. Seat wrenches come with either tapered or stepped ends. Insert the end of the seat wrench that fits the shape of the opening in the seat and turn it to the LEFT (counter-clockwise) to remove it. As the saying goes, "rightie tightie, leftie loosie". If you are using a seat wrench with a tapered end, tapping the wrench lightly into the seat helps to keep it from coming out of the seat while you are turning it.
If the seat has a slot instead of a square or hexagonal opening, you will need to find a screwdriver with a flat blade the same width as the slot. Insert the blade into the slot and tap it lightly to keep it from slipping out. Turn the screwdriver counter-clockwise to remove the seat. It helps to grab the shaft of the screwdriver with pliers or an adjustable wrench to help you turn it.
To install the new seat, apply pipe joint compound or thread tape to the threads of the seat. If using thread tape, face the threaded part of the seat towards you and wrap the tape in a clockwise direction. Wrap the tape around it two or three times. It is good to let the tape cover the shoulder portion of the seat to help it seal against the base of the faucet. Insert the seat into the faucet base and tighten by turning clockwise. Tighten it securely, but do not apply excessive force. If you tighten it too much you could break the top off of the seat or damage the threads in the base of the faucet.
- Is there a way to tell what stem I have without removing it?
It is nearly impossible to identify a stem without removing it. Even when you have removed the stem it is not always easy to identify the replacement, there are so many different parts of the stem that must be matched up that even if you know the manufacturer (which is rarely the case), identifying it without removing it would be a real long shot. Identifying the seat is often a big help in correctly identifying the stem.