No pressure, shower

Just bought a home built in 2007. I have great water pressure in the entire house except for the master shower. The whole house is done in Pex. The basement is finished with a drop ceiling, but I can see what looks to be a professional job and I can follow the entire system to each section of my house.

The only thing I can't see is where the pex heads north into the wet wall behind the shower. I don't have an access panel behind the shower nob or shower head, but if I had to cut an access, I could do so through our walk in closet.

I've taken the shower head off and turned on the water and it just limps out. I've tried to adjust the pressure through the knob, but it's always set to the max.

In the master bathroom I have double sinks, toilet and a separate tub all plumbed with pex and seem to have great pressure. The tub has a separate wet wall and is not plumbed together with the shower. The sinks and toilet are opposite the shower and tub and are plumbed with their own wet wall.

I have an upstairs shower that has pressure that blows you against the wall, but this mystifies me? Why pressure in the entire house except the master shower? Should they have reduced the size of the line when it turned north from the basement to the shower?

Any thoughts or suggestions would be helpful.
emanoh

Sounds like a stuck balancing spool. It happens if the faucet hasn't been used for some time. Replace the cartridge in the shower. If it's Moen or Delta give them a call and they will send you a replacement free of charge.

Turn the main off. Then have someone crack the main back on slowly. Might be debris in the lines. If not, definitely the cartridge.

OK, I've taken apart the shower control dial and replaced the cartridge. By the way, Moen can kiss my a$$. It took me 2+ hours to remove the 1222 cartridge. It's really not that old and not that corroded, but their simple online tutorials where you rotate 45 degrees and gently pull it out are BS. I was eventually able to get it out in pieces and am still perplexed what was holding it inside the cylinder.

Nonetheless, I removed the old cartridge, installed the new one, got everything put back together. The moment of truth after I turned the water back on. Bang, no change the water limps out of the gooseneck just as poorly as before.

I am perplexed, again, the whole house has great pressure except the master shower. I can see the pex from the basement to where it goes into the wall behind the dial. After I did this last fix, I can see that there is pex going from the dial to the gooseneck. I've fuddled with the only moving parts in the system. I'm pulling my hair out at this point. I guess there could be a blockage in the pex tubing but that could be anywhere?

More thoughts?

There is a puller designed to remove that cartridge. The way you described removing the old cartridge part of the rubber seals may be lodged in the water passages in the valve body. Remove the new cartridge and check inside the valve body for pieces of the old stem. You may have to turn the water on slowly to blow them out. Have someone turn the water on while holding your hand over the opening.

Yes, I know there is a puller, but I didn't have one when this 30 second job took over 2 hrs and went into the night. Plus I needed to turn the water back on for the AM and I was at a point of no return. There are volumes of videos and postings where the cartridge gets stuck and the puller doesn't work. The design just sucks. Some come out easy, some don't

Nonetheless, I was able to get it removed, cleaned and cleared out the cylinder and installed the new cartridge. After turning water, back on, I got the same limp wristed flow of water.

So that is where I am, back where I started. New cartridge, ****ty water presssure and still scratching my head.

Did you remove the shower head and then check delivery?

Yes, when I removed the shower head and turned on the water it just limps out of the gooseneck, no pressure. Only thing the shower head does is seperate the stream into multiple little crappy streams of no pressure. I can take a shower, but you feel like it takes forever to rinse.

If the rest of the house has adequate pressure, there has to be blockage somewhere(s) in that circuit.

Don't feel bad, my record for removing a 1222B is over 3 hours. Basically had to drill it out in tiny little pieces, what a nightmare. Others I have changed in 2 minutes. Ya win some, ya lose some.

Was there at one point good pressure in that shower? Or has it been poor since it was purchased? It could be a water volume issue, not pressure, if it's all piped in lomg runs of 1/2" pex.

It's been crappy since we moved in. I was thinking the same thing about the run. It is a long way from the source. Probably the longest. But the other 3 water sources in that bathroom are fine. Pressure in second story shower is fine, so I am back to thinking it's a blockage somewhere.

Here's a little secret for everyone. If you get those Moen cartridges stuck, and the puller isn't doing the job, or you cannot find one, get a big bolt extractor or nipple extractor. Most hardware stores have these. You can remove the internals by removing the snap ring, and then you can install the extractor in the brass outer part of the cartridge.

By the way, don't forget to remove that retainer clip!!!

Shower update. So after futzing with our master shower, trying to get any flow/pressure, I did everything I could do, including replacing the cartridge. I wasn't ready to start choping the pex if I didn't know where to start looking. I finally broke down and called a Plumber. Walked him through what I knew and had already trouble shot and he was scratching his head as well. It came down to two things; a blockage in the line above or below the knob/cartridge or the whole cartridge behind the shower knob was faulty. One was more expensive than the other and required punching a hole in the wall. We tried disolving any crud in the lines before trying option #2. It worked.

So for shower only units, they don't have any way to flush out debris. A tub/shower can flush out junk through the tub spicket. On shower only units junk can collect between the knob/cartridge and the shower head. The chemicals they used fixed the problem and now our master flows like Niagara falls. I learned something, only cost me $237.....ha! We can use white vinegar in the future if we have issues again. I have so much pressure I can hardly stand up. There you have it. Problem solved. I wish I got the name of the stuff he used.

He flipped the goose neck upside down. Filled it with the disolver, soaked the shower head in the goop. Let it soak 10-15 min. Put everything back together and now my wife can actually use the shower in our master bedroom.