Strange Water Pressure Issues

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  #1  
Old 11-05-18, 08:25 AM
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Strange Water Pressure Issues

We remodeled one of our bathrooms, which included new water pipes. after finishing the piping and turning the water back on everything seem to be working fine. But for whatever reason all showers in our house now have little to no water pressure coming from hot water. The kitchen faucets and the bathroom sinks work fine, the issue seems to be only with shower heads. I took the heads apart yo check for something but they were clear. any ideas?

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  #2  
Old 11-05-18, 09:06 AM
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Water doesn't know where it's going but you would notice an overall pressure change more from a shower than a sink.

Something in the new plumbing has changed the water pressure?
 
  #3  
Old 11-05-18, 09:17 AM
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The only difference is the new bathroom is copper pipes as appose to galvanized steel from the main lines. The new pipes for the remodel bathroom there are 3/4 copper pipes connected to the old 3/4 steel pipes and then they branch off to 1/2 copper pipes to each fixture, Actually all of the bathrooms are the same way since they were remodeled at some time so they all have copper piping but the main lines are still steel (which is the next project to remove and install copper, but i don't think that is what is causing the problems since the cold is fine).
 
  #4  
Old 11-05-18, 09:34 AM
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I could still be the galvanized line - I assume you still have galvanized between the water heater and the new copper.
 
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Old 11-05-18, 09:58 AM
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yes steel pipes to water heater. But I also put shutoff valves to the new bathroom (in between where it goes from galvanized steel to copper) so when i close them its like the new bathroom doesn't exist, but the water pressure on the hot water for the 2 other showers still doesn't work. All I can think is maybe the valves on all 3 showers got messed up or the water heater got messed up somehow, but it doesn't make sense because all sinks are working fine.
 
  #6  
Old 11-05-18, 12:32 PM
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So all the pipes after the water heater are new copper ??
 
  #7  
Old 11-05-18, 12:48 PM
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90% of it. From the water heater to the crawlspace, about 6 feet is galvanized steel then from there on is copper to all faucets/showers.

The cold pipes supplying the water heater are all galvanized steel.
 
  #8  
Old 11-05-18, 01:06 PM
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You could try flushing the water heater in case there is any trash built up in it. Shower and tub use more volume than sinks but I wouldn't think there would be a big difference in pressure.
 
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Old 11-05-18, 01:10 PM
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Like drain the water heater? I guess that better then having to repipe everything. Ill give it a try. there is nothing on a water heater that controls pressure out right?
 
  #10  
Old 11-05-18, 01:15 PM
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Be sure you turn the water heater off [if electric] before you open the valve at the bottom. Often you only need to flush out a few gallons - you'll be able to tell by looking at the water if it's clean or has a bunch of sediment. The water pressure coming out of the water heater should basically be the same as the pressure coming out.
 
  #11  
Old 11-05-18, 09:21 PM
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That wasnít it ..i took apart the water heater on/off valve to see if anything was in it but it was clear. I measured the water pressure on water coming from the city through a faucet in the front of the house and it was 60psi. I then measure the water heater pressure through the discharge spout and it was also 60psi. So looks like 60psi going into water heater and 60psi going to house.. seeing how itís only the showers affected it looks like something g damaged all the valves in all 3 showers
 
  #12  
Old 11-06-18, 03:50 AM
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Maybe your new shower head is one of those "water conserving" shower heads with the little constricting plastic washer (red or blue) that's performing its job with too much enthusiasm, and simply has to be removed in order to improve the flow . . . . they take a Ĺ" pipe and reduce it to about a ⅛" hole. and then all you get is a dribble !
 
  #13  
Old 11-06-18, 08:35 AM
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If it was just 1 shower valve it would make sense but its all showers in the house and they are all different brands. I'll try replacing one first and see how it goes. Its getting frustrating and I was just going to call a local plumber but knowing plumbers around here they will just say repipe everything.
 
  #14  
Old 11-06-18, 09:37 AM
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This is fuzzed up in my brain and I havenít really thought it through, but itís coming out of my mouth anyway.

In terms of length, is there is now much more copper than steel leading to the hot side of the shower valves, compared to the cold side leading to the shower valves? I was thinking that if these are pressure balancing valves, and if they see a much higher pressure on the hot side than on the cold side, would they reduce the hot pressure? The pressure is probably a lot better through the copper piping.

I really donít know how those valves work but I was thinking the pressure on your hot side might be a lot different than on your cold side because those galvanized steel pipes can really build up rust on the inside, and that might impact the shower valves balancing act. In other words, would the valve now kind of over-restrict the hot because there is Ė NOW - such a big imbalance between the hot and cold side?

But I donít know if this makes any sense at all Ė LOL!
 
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Old 11-06-18, 10:43 AM
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Actually all of the bathrooms are the same way since they were remodeled at some time so they all have copper piping but the main lines are still steel
So only one bathroom plumbing was changed, the others were done in the past and now they are all the same, main steel line, copper branches?

All were fine prior to the remodel and now all three are different?

Where is the most recent bathroom in relation to the others?
 
  #16  
Old 11-06-18, 01:41 PM
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All were fine prior to the remodel and now all three are different?
That's the same thing I find puzzling. What could the explanation for that be!
 
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Old 11-06-18, 02:22 PM
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Where is the most recent bathroom in relation to the others?
Still would like to know location of recent work!
 
  #18  
Old 11-06-18, 03:08 PM
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OK, this sounds stupid but here goes. Plumbers sometimes have to use something like bread to hold off all moisture in a pipe while they sweat the copper. The bread can be very hard to dissolve if its crammed into a small pipe but will dissolve. However, a rag, if used, could be another thing.

Can you map out the location of any valves and any turns in your new piping system and try to visualize if there is a single point where a stoppage would affect all the showers?
 
  #19  
Old 11-06-18, 04:56 PM
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If there's old galvanized water piping, there's a very good chance that it's filled with rust, even if it looks good on the outside. When someone goes to do some work on it -- no matter how careful they are -- chunks of rust can, and often will, break off and create a blockage/restriction somewhere.

If that's the problem at your place, re-piping may be the only solution. You can mess around with back-flushing and whatnot, but it's just as likely to make things worse as it is to make them better. And if a glob of rust has gotten into the copper, you will have to back-flush -- after the re-pipe.

Note that the water pressure will be the same throughout, but a smaller passageway (like one that's restricted) will deliver lower volume. That is, you can have 60 psi in a 2" copper water line and 60 psi in a 1/4" water line, but you won't get much volume through the 1/4".

 
  #20  
Old 11-07-18, 06:19 AM
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Your answer makes sense to me. But before repiping again, could he not put in a gate valve where the galv. and the copper meet and put in a tee beside the valve on the copper side, pointed down? This would allow the backflush to clear out the pipe without further disturbance to the rust in the galv pipe. Then he could cap off the tee and move forward with life.
 
  #21  
Old 11-07-18, 09:17 AM
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But how can a blockage account for all 3 bathrooms experiencing the same problem?

(1) Each bathroom is serviced by a 3/4 branch off of the 3/4 hot main.

(2) From that 3/4 branch there is a 1/2 branch to the hot side of the bathroom sink.

(3) Also from that 3/4 branch there is a 1/2 branch to the hot side of the shower.

(4) The hot side of the sinks in each of the 3 bathrooms is fine.

(5) The hot side of the shower in each of the 3 bathrooms is NOT fine.

Where would a blockage be to explain that?
 
  #22  
Old 11-07-18, 09:25 AM
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So OP has not responded where this newest repair is located in relation to the other 2.

First, sinks use a lot less water, hot or cold, so if there if a VOLUME decrease then sink will feel ok where a shower with higher GPM will feel like a big loss in water.

That is my opinion, during the last upgrade something happened to block one of the main lines which now effects all the bathrooms.
 
  #23  
Old 11-07-18, 12:15 PM
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Yep, that would explain it if actually the bathroom sinksí hot side have also been degraded, not just the shower hot side.
 
  #24  
Old 11-07-18, 10:26 PM
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If there is rust in the galvanized and it was disturbed (with say, a sawzall) more than one chunk of debris may have been dislodged. Debris will wind up in places like an angle stop, where the port-size is reduced. On more than one occasion I've pulled the stem of an angle stop and seen a piece of debris stuck in there.

Right now I'm looking at a monitor and don't know if that's the case or not, but with old galvanized piping involved, it seems like a possibility.
 
  #25  
Old 11-08-18, 01:22 AM
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ok sorry for late reply this was happening. First of the problem only with the hot water in the 3 showers, cold is fine and all sinks are fine. Prior to me remodeling the bathroom there were 3 working showers. The piping for all the water lines under the crawlspace for both hot and cold are 3/4 steel, once they get to each bathroom they turn to 1/2 copper. From the water heater a 3/4 steel pipe comes out down to crawlspace (about 6 feet) into a "T" connection, the right side of the "T" goes to one bathroom, kitchen and laundry, the left side goes to the other 2 bathrooms.

I remodeled the first of the 2 bathrooms on the left. I replaced about 10 feet of steel 3/4 pipe leading to this bathroom with 3/4 copper and added two shut off valves where the steel and copper meet so i could shut off water while i worked on bathroom

There is a good chance that rust or debri got loose when i had to cut a section with saw. But I didnt think that could be the issue since all the other sinks are fine. But now I think that might be it.
 
  #26  
Old 11-09-18, 12:46 PM
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I guess the debris explanation really could be the answer as others have suggested. I was thinking there is no way it would only affect the showers but not the sinks, but I think now that logic is wrong. Maybe the debris just washed right through the sink piping but got stuck in the shower valves. Seems like that could be the case in all three bathrooms because the shower valves would be a lot different than the sink valves. At least it seems that way to me.

Maybe you should try to clean out one of the shower valves (not the shower head) and see what happens. If they are the cartridge kind I think those are pretty easy to clean. You would just pull out the cartridge and then turn on the water to flush everything out.

Seems like that would be a good idea but maybe the other guys will have an opinion on that.

(also, maybe you were lucky and did not dislodge any debris when you messed with the cold so that's why there are no problems with the cold)
 
  #27  
Old 11-10-18, 06:49 PM
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If it is chunks of rust from the old galvanized, then where they go is unpredictable. They would be tend to be propelled towards whatever fixture is opened first.

Note to Lakeseed -- it's an interesting idea that /might/ work, but I think the OPs efforts are better directed to replacing the galvanized piping. If it is rusted internally to the point that it's causing problems, it's time for it to go. New full-port piping would deliver better volume. It's probably done a good job for a number of decades and it's useful life is over.
 
  #28  
Old 11-11-18, 07:11 AM
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First of the problem only with the hot water in the 3 showers, cold is fine and all sinks are fine. Prior to me remodeling the bathroom there were 3 working showers.
Well Iím picture happy and I did this for myself to kind of pictorially represent the puzzle Ė to my mind anyway, so here it is for what itís worth. How are 10,12, and 14 affected after the new piping was installed, but everything else is still OK?
 
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  #29  
Old 11-11-18, 08:48 AM
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Easy, something occurred in #1 at the time of the rework!
 
  #30  
Old 11-11-18, 09:28 AM
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How did it NOT affect 9,11, and 13 when it DID affect 10,12, and 14?
 
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Old 11-11-18, 11:05 AM
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It did, I keep stating a shower used a ton more water than a sink, if water flow was cut in half you would notice it in the shower but not at the sink!
 
  #32  
Old 11-11-18, 11:32 AM
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I did take note of what you said, and it does sound like a good explanation ... but it sounds like parentof3 disagrees as of 11-8

and all sinks are fine
You would think that if the shower was very bad something would have been noticed at the sinks - but maybe not. Maybe better pressure tests are needed.
 
  #33  
Old 11-11-18, 12:51 PM
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Maybe better pressure tests are needed.
You need to do some volume testing, not pressure testing.

I can get 60psi through a straw, cant get 5gpm!
 
  #34  
Old 11-11-18, 10:09 PM
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Which pipes in the drawing are galvy? If there are 3 disparate low-volume points, it kinda point to 3 problems. No one point would cause it. Random bits of debris /might/ be an explanation. Or not. Like I said, I'm here looking at a monitor. It might be three balancing spools that are stuck, but that would be an unlikely coincidence. Things need to be taken apart by two people. One to look and one to turn the water on & off. Then you might get a better idea.

And, come to think of it, when's the last time anyone saw intact galvanized water pipe? I don't think it's been installed much since the '60's (a decade from an earlier century).
 

Last edited by steve_gro; 11-11-18 at 10:26 PM.
  #35  
Old 11-16-18, 09:16 AM
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Man that's a good drawing!!!. That's exactly how my setup is, i was trying to use MS paint to draw it lol

I didn't come back to this post since I had given up and was going to just wait until I have money to re-pipe everything at the bottom (although I think since everything else is working fine I could have gotten a couple of more years out of it),

From the drawing 1,2,3, 4, 6 and 7 are still galvanized pipes. 1 and 2 are about 6 feet long each, 6 is only like 12 inches, 3 is about 3 feet , 4 is about 10 feet and 7 is about 1 foot (not sure if those numbers help.

I haven't had time to look at cartridges since when i looked at one i couldn't figure out how to remove it, looked kind of old. One thing my wife notice was that now when we turn hot water it makes a tapping noise but again sinks work fine.

My guess is there is some debri restricting it at number 1 pipe in the diagram. Here is the dumb question of the day, if I remove the valve from the hot water from one of the sinks so that only the 1/2 copper pipe is sticking out so it has full flow, can i then go tap/hit on pipe 1 to loose any debris and hopefully flush out through the open pipe ? maybe do it to the cold also.
 
  #36  
Old 11-16-18, 09:28 AM
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can i then go tap/hit on pipe 1 to loose any debris
Look at picture of clogged pipe in post 19, chances are if it's plugged, it's plugged along the entire length of pipe, it's not going to be flushed out!
 
  #37  
Old 11-16-18, 09:30 AM
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I guess we will be saving on water for a while until I re-pipe everything. Thanks to everyone for your help!!
 
  #38  
Old 11-17-18, 10:21 AM
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While repiping is a good first step, I believe it won't entirely solve your problem till you back flush the hot lines leading to the tub/shower faucets. I had a similar yet slightly different problem in a 2 story house (90 years old) and back flushing solved the problem.....for a year or two anyway. I found that extremely fine sediment wouldn't stop the flow to toilet or Kohler faucets with stems, not washerless, but it would drastically reduce flow to the Delta tub faucet. I had installed ball valves and dielectric unions in the basement to separate the new copper lines in the basement from the galvanized steel lines that run through the walls to the 2nd floor bathroom. It was easy, but just took a few trips up and down stairs connecting the three levels. That was the hardest part. I see a good application for pex pipe to be fished through the walls to feed that bathroom in my future.
 
  #39  
Old Yesterday, 07:33 PM
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The drawing got me curious and I've updated it to reflect the OP's input. There are two tees that -- if debris were loosened -- could impact all three showers. The 2-4-1 tee and the 2-3-6 tee. Sawing where the new shutoff is indicated could've vibrated both of them enough to free up some chunks of rust.


 
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