Horrible pressure, shower

[emanoh]

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 altready 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.

 

[Dj2]

Good chance that your problem is in the shower valve.
Can you remove the cover and post a picture of the valve?

 

[Sponsor]

 

[emanoh]

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?

 

[CountryBumkin]

I'm not a plumber - so maybe one of the experts can add to this ---
Some of the shower valves have built in shutoffs. Is it possible that your shower valve has these, and if so, they were never fully opened when shower was installed (assuming problem has been there since you moved in)?

 

[hj]

If EITHER water line is restricted, the cartridge will restrict the other line to the same extent so you have to find out if either line is faulty.

 

[Jadnashua]

Some of the valves have in-line filter screens. You'd need to check the parts list to see if your specific one does.

Pex, if run properly, doesn't kink after the fact, but if they tried to bend it into a tighter radius than design, it may have kinked. If you need the sharpest bend, it may be best to use one of their bend supports. Unless it is pex-a, if you have a kink, you have to cut the problem out and install a fitting. If it's pex-a, you can restore it with a heat gun, but if the bend is too tight, it may just happen again. In this case, a bend support might prevent that.

 

[emanoh]

When I had everything apart and I could see behind the fiberglass shower stall. The brass cylinder that connects to the dial and where I just replaced the moen cartridge, connects from the basement to the Pex. From the brass cylinder there are hot and cold brass 90 degree bends to where the pex connects in a straight line. I don't believe the pex is bent 90 degrees to connect to the cylinder. I will double check. The install looks proper and doesn't appear kinked. the connector bands looked properly installed. There are no shut off valves behind the shower dial. I had hoped this was the case, but it's just the brass cylinder housing where the pex is connected from the basement, runs through the cartridge and then heads north to the shower gooseneck.

Maybe there is a blockage at that one of the hot or cold connection points where it attaches to the brass 90 degree? But I don't seem to get more/less of hot or cold when I turn the dial. The regulation of hot and cold seems to be correct and one isn't more slow than the other.

There are not a lot of moving parts in this equation, and the rest of my home flows like Niagra Falls, so that is what is confusing.

 

[emanoh]

Some of the valves have in-line filter screens. You'd need to check the parts list to see if your specific one does.

Pex, if run properly, doesn't kink after the fact, but if they tried to bend it into a tighter radius than design, it may have kinked. If you need the sharpest bend, it may be best to use one of their bend supports. Unless it is pex-a, if you have a kink, you have to cut the problem out and install a fitting. If it's pex-a, you can restore it with a heat gun, but if the bend is too tight, it may just happen again. In this case, a bend support might prevent that.

I can only see from the basement to where it disappears into the floor behind the wet wall, it's pretty much a gentle, almost vertical bend. No kinks. I don't have an access panel behind the shower, it's our master closet if I do eventually have to punch an access panel. From where it disappears in the basement it looks like a straight run to the shower knob cylinder. So no kinks. I know....confusing and confounding.

 

[emanoh]

I'm not a plumber - so maybe one of the experts can add to this ---
Some of the shower valves have built in shutoffs. Is it possible that your shower valve has these, and if so, they were never fully opened when shower was installed (assuming problem has been there since you moved in)?

View attachment 36107

Yeah, unfortunately I didn't have those smaller shut off knobs when I removed the dial to see the cylinder behind the shower stall. I had hoped.

 

[emanoh]

If EITHER water line is restricted, the cartridge will restrict the other line to the same extent so you have to find out if either line is faulty.

This is good info that if one line is blocked or restricted the cartridge will equalize and restrict the other. The question is that if this is the issue, which line? Ha!

 

[Reach4]

I don't know about how those work, but if you have somebody turn on the water (temporarily) with the cartridge out, and you are in there behind the shower curtain, you may see two incoming flows, and one may be much greater than the other.

I am hoping that the flows would be clear, but I don't know. Its free to try.

 

[CountryBumkin]

I understand that with the valve set to warm, a restriction in the cold side would then reduce flow of hot side (so as to produce warm water). But if you turn on "full" cold, would the valve then allow maximum flow of cold side/line?