The service call to get someone there, at least $35 plus the time they are there. 30 minutes top for a difficult faucet and a slow worker. That could be $60 to $85 an hour depending on where you are at Plus the parts which if it is just washer, cups, O rings could maybe go as high as $10 retail but more from a plumber. You could spend $100 plus depending on location and greed of the plumber. A $10 Plumbing for dummies and $5 to $10 in parts is a much better bet. If you do it yourself, shut the water off first. It's really not that complicated.
Replace rubber washers and possibly metal seats in the faucet
There are many things that can cause a shower faucet to leak. Some of the most common reasons for this are poor quality washers, washers are the wrong size,loose nuts, build up of residue on the faucet inlet.
You take it apart and change the seals and washers.
Stores usually have their own section for portable washers or mark them as such. These washers don't differ much from standard washers. They nearly always have wheels, are of a more compact size and provide ways to temporarily connect them to a faucet or water provider.
Try squirting a little white vinegar on the washers. This will dissolve any mineral deposits that are keeping them in place.
Some common cause for a leaky faucet are, washers that haved aged and become brittle, washers that have broken or expanded, and sometimes it's the taps that need tightening or removal for addition of washers. A great article on this can be found at- http://www.wikihow.com/Fix-a-Leaky-Faucet. Also to be noted is that sometimes the metal has expanded too much from use and or pressure and could affect any mechanism from the stem to the nozzle. You clould use teflon tape in some cases or plumbers caulk, but most times you need a replacement.
You can fit new seals, washers and possibly the seat of the seal.You can fit new seals, washers and possibly the seat of the seal.
Its not changing from faucet to spray itself that burns, but the temperature of the water and where your body part is in relation to the water.
The ball very seldom is the problem it is the springs and cap washers
what is the GPM rating from the old to the new the lower the GPM the slower the water. Sometimes there are restrictor discs (washers).
Could be bad washers and they need to be replaced or something broke in the handle of the faucet.
To remove old shower pipes to install a new shower faucet, turn the main water off first. Then either cut the pipes at the joints or unscrew the washers holding the pipes together.