Install a new pressure balancing valve in shower which helps with problem.
If you mean shower valve, screws are for shower valve coverplate.
Behind shower valve handle and trim plate
You replace it. If it's a squeal, you replace the shower head fist. If that doesn't make the noise go away, you replace the shower control valve. Odds are since you came online to ask how to fix it, you're not qualified to replace the control valve. Call a plumber now or call a plumber and a drywall contractor to fix it after you make your "repairs"
A leaking shower valve by installing a new cartridge.
If the noise is only for a few moments after taking a shower, its the expansion on the hot water side. Water lines going through studs will expand and make noise. the only way to fix this is to get in the wall and either loosen the pipe or tighten it with a shim.
Standard height for ADA (handicap) is 42 " center of valve to shower floor.
Cut out the drywall in the wall behind the shower. Replace the valve. Patch the drywall.
Drag them to the red boxes in the workroom , they will automatically fix the shower
Shower may have an anti-scald shower valve installed. If so, shower valve can be adjusted to desired temperature.
changing a shower valve can be sometimes impossible with out cutting a hole in the wall behind it. If you have a shower valve that is leaking through the valve and out of the shower head when shut off then I recommend trying to find new cartridges or replacement seals for the valve. If you need to replace the shower valve then I would cut a hole in the sheet rock behind the shower valve big enough so you have enough room to replace it. Sometimes if you can't get behind the shower wall and your water pipe isn't galvanized then it might be possible to change the valve through inside the shower but it can be a real struggle and most of the time you will need a wider trim plate. If you don't have much experience in soldering or using pex pipe and fittings then I would save you a headache and call a service plumber.
The mixing valve is messed up...It's easier to fix than figure out.
You have to dismantle the control valve and fit new rubber washers. Instructions come with the washer kit.
You can call a professional in your area to come fix your shower or do it yourself by following a tutorial. How you fix your shower depends on what it is made out of such as fiber glass.
First decide if you want to take a shower valve repair yourself, or contact a plumber. If you decide to repair the shower valve yourself, first you will need to shut off all water to the shower and tub.Next, turn the valves to the on position to relieve any pressure, and remove the set screws. Next, remove the trim ring and save all of the gaskets. Take all of the valve parts to a home improvement store where they will assist in finding you all the replacement parts. Lastly, you'll need to put everything back together in reverse order.
depending on your spout diverter if its a valve or is it on the spout it self, if the diverter is on the spout then your diverter is not letting full flow of water out of the spout and its putting enough pressure to allow the water out of the shower head, I had this problem before and if you change the spout it should fix the problem. If you have a 3 way valve which is on the wall then i would suggest replaceing the parts in that valve if possible other wise change out the divert valve. If your broke like me and want a cheap fix then put either a water flow resistor or a shutoff right before your shower head.
You repair or replace the shower control unit.
The valve is not be diverting all the water. This valve may need to be replaced.
With a new valve gasket
Your water pressure is low. Consequently, when cold water is diverted to another application such as a toilet or a sink, the amount of cold water available at the shower mixing valve decreases as the low pressure is unable to keep up with the shower's demand. This causes a hotter mixture at the shower head. The solution is to either improve the cold water supply to the shower or to replace the shower control valve with a temperature compensating type. Pressure balancing is the cheapest and simply changes the shower temperature according to the pressure in the cold and hot water lines. When the toilet or sink is used, reduced pressure to the shower valve is detected and the valve reduces the hot water pressure, thereby maintaining the temperature. The more sophisticated approach is a thermostatic shower control valve. These are significantly more expensive, but will not reduce the pressure at the shower head (a drawback of the pressure balancing valve). The thermostatic valve would be required when one shower control valve is operating several shower heads. Moen, Kohler and Delta all make both types of control valves. They can be readily obtained from a local plumbing supply house.
Some shower valves have integral stops which can be accessed by removing the trim plate. Most shower valves don't have these and the water is shut off by turning off the main valve to the house or apartment.
Though not a plumber, I can say that shower valves are usually made of brass(a very good material). Therefore they are also expensive to replace (50 dollars for the valve, 150 dollars per shower valve if done by a competent plumber). Therefore, when you notice a leak coming from your shower, try to replace the seat washer (usually the hot water side needs to be replaced first). If you still have a leak, it's time to replace the shower valve.
42 to 48"
The valve in the shower control needs to be renewed.
Replace the shower valve.