We have low water pressure in our MBR shower only. We have replaced the stems and seats which corrected the cold water going on and off we turning the handle. Also our faucet (shower only) is Price Phister (installed about 10 yrs ago). Could this only be a clogged shower head? That's the next step. Another problem is the water gets too hot if you're showering and someone turns on another faucet in the house. I thought it might be the valve but a plumber told me all parts are replaceable in a valve and you wouldnt need to rip out the wall. What other parts should I check? All these problems began about a year ago. Any help would be appreciated.

What year was your house built? Do you have galvinized supply pipes? If so & they are quite old you may need to replace all your lines with new copper or plastic ( I would use copper)or at least the feeds to your MBR shower. Do your neighbors have low pressure problems also? If your supply (city or well) pressure is fine chances are the problem is your interior pipes. I would check the pressure where it enters the house first. This is not an uncommon problem with older homes that have galvanized pipes since with time they will corrode & not always evenly across the supply grid. Hot water pipes tend to corrode first. But the good news is if you need to replace the pipes most people can learn to install copper or plastic quiote easily.

Sounds like the faucet cartridge might be bad. This is a replaceable unit that is fairly simple to replace. This is assuming that you have a single lever faucet. If the faucet washers were not the proper ones that will also effect the water pressure. This assumes you have one cold and one hot faucet. However if the pressure was low before you replaced the washers, sounds like the pipes are plugged with hardness.
As far as the water temp changing, if again the valve is a single lever faucet the new cartridge will or should correct the changes in temps. AS these have a anti-scald feature.

I agree that the problem might be galvanized pipes. If you have them then you might check the filter in your shower head. Rust from the galvanized pipes sometimes breaks off and clogs the filter. If this is the case then it is a very easy fix. Just pull the shower head, remove the filter and wash it out.

It sounds like you have separate hot and cold valves, since you refer to stems and seats. This type is not pressure-balanced, which is why the temperature of the water in the shower changes when someone elsewhere in the house draws water out of the system. A pressure-balanced mixing valve will have either a floating piston, or a diaphragm which floats left and right within the valve body, adjusting the pressure of the "high side" to that of the low. The net effect is to reduce the volume of water being delivered through the valve, while holding the temperature of that reduced volume constant. Once the draw-off elsewhere in the house has been completed, the valve will respond to deliver the full volume available to it through the piping to which it is connected, but keeping the temperature constant.

As mentioned, any debris within the line(s) can mess up the operation of the valve(s). You could try shutting off the water supply to the valve(s), removing the stems and bonnets, where the packing sealant is located, then, with someone watching and directing the water, turning on the water supply again for a short time to blow out the lines through the now open valve(s). This will normally flush out the lines and the valve bodies, whereupon the water can then be shut off again, the valves re-assembled, and tried again, checking for leaks.

If it were my house, I would bite the bullet for a pressure-balanced mixing valve, assuming that there are no issues involving galvanized iron, or brass, piping, and that your water supply is also not problematic, as could be the case with a well delivering sediment to the piping network.

Hi,

My mom had a similar problem in West Texas...hard water...50 yr old house...Master bedroom shower. I replaced all replacable parts, etc., blew out line with water, etc.

She finally got success when some friends from the church came by...turned off water to house...opened valves in bathtub in other bathroom...attaching air compressor to shower lines with valve stems removed. This blew the sediment out of the elbows in the pipe at the junction of the floor and the wall. Shower has great pressure for the first time in five years.

It's worth a try...just be sure to open another valve to releive pressure on the pipes when you turn on the air...(don't want pipe damage or water heater damage).

Bruce

I had this exact problem with my Master Bath shower, in So Cal where the water is very hard. The problem was the shower head was restricted with calcium deposits. I took off the shower head and soaked it overnight in a solution of 50% water/50% vinegar. The next day the soaking container had lots of whitish particulate in it after rinsing the head out. This solved the problem, and I have to do it about every 5 years. Give it a try before you try anything more expensive.

I have a 108 year old house with tons of messed up plumbing, much of which made no sense at all. I found the piping was almost completely closed up with rust and minerals. I ran an electrical wire snake through the lines and that really helped unitl I could get around to replacing that section of piping. the small snake fit just inside the line and was flexible enough to turn the corners in the lines. Maine water is known for hardness and minerals, so I also have to clear the shower head and the aerators on the rest of the faucets.

Four years ago, I had to replace ALL the copper piping in my home, due to high acidity and sediment. A year or so later I has a water treatment system installed. Everything was fine, good water pressure, gradually lost pressure in kitchen and bathroom sink but not the tub. Wasn't a huge problem but then I developed a leaky bathroom faucet. I replaced the seats in the bathroom faucet. No good. I installed new cartridges which stopped the leak but pressure was nearly zero. My plumber wanted me to replace the faucet and turn up the water pressure! Wouldn't you know it, I went for the simplest solution: I took the screen out of the end of the spigot and cleaned it out! Magic! So I cleaned out the one in the kitchen, too. Apparently I had a lot of sediment in those pipes remaining frrom the days before the water treatment system. Sometimes the stupidest solutions are the best.

I had your same problem you are discussing. I did some searches and came up with www.takeashower.com. I have owned the shower head for about 6 months and it is terrifc. I just bought the cheapest one they had to give it a try.They have a guarantee that I couldn't help but try their product. It worked for me.