Almost no Hot water in shower

Discussion in 'Plumbing Forum' started by frankflynn, Feb 10, 2013.

  1. Feb 10, 2013 #1

    frankflynn

    frankflynn

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    I have a 1930's house. This shower was added a little bit later. All of the plumbing involved here is galvanized and at least 50 years old. Here is the shower - hot water full open:

    [​IMG]

    The cold water in the shower, Toilet and Sink (both hot and cold) work fine and have good flow. But the hot water in the shower is severely restricted.

    It has separate hot and cold valves and I have taken the valve apart to clean it out (nothing much to clean out). I turned on the water to the house while the valve was apart hoping to flush anything out of the like (the pressure coming out of the hole was not very much).

    So:

    Am I correct in assuming that the problem is rust in the hot water line?

    And the only way to fix it is to replace the pipe?

    Most of the rest of the house is already copper and while doing another project downstairs I ran new copper hot and cold lines to just behind the shower (these are capped and have nothing to do with the current system).

    The problem with switching to the copper lines is this shower is in a dormer and although it's possible to crawl behind the shower through the attic space you can only get to the bottom 2' or so. Since the sink right next to it has good hot water flow I'm assuming the blockage is likely to be in the shower wall and the only way to get to is is to rip out that wall. That might be the thing to do if time and money were not objects but sadly they are.

    Thanks for any thoughts.
    Frank

    shower_slow.jpg
     
  2. Feb 11, 2013 #2

    Wuzzat?

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    Last edited: Feb 11, 2013
  3. Feb 11, 2013 #3

    frankflynn

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    Well - most of the rest of the house has been re-plumbed already. Perhaps that's why I'm broke and did not particularly want to rip out these walls just yet. I do intend to remodel that whole bath but if I have to do it now it will necessarily be a much cheaper job perhaps on the order of a fiberglass panel wall that I will rip out again in a few years.

    That might be for the best anyway.
     
  4. Feb 11, 2013 #4

    kok328

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    You might try "snaking" out the line and see if you can bust up some of the obstruction in the pipe. Keep in mind this will be a temporary fix at best and rust can be hard to chip away with a plumbing snake (I'd try an electrical fish tape for better results).
     
  5. Feb 11, 2013 #5

    Wuzzat?

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    "Scaling" tools & bits remove rust but I'm not sure they will work in a small ID pipe.
    You shouid probably be getting enough GPM out of that pipe so that you can fill a 5 gal. bucket in a minute.
     
    Last edited: Feb 11, 2013
  6. Feb 11, 2013 #6

    nealtw

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    Have you taken apart the tap, if this is old style you could have a washer stuck in there when the screw no longer holds it to the valve.
     
  7. Feb 11, 2013 #7

    Fireguy5674

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    I had a similiar problem years ago. When I took down the 1/2" galvanized line it was so full of corrosion and crap I was amazed any water got through it. I could not see a hole. A fifty year old galvanized hot water pipe is most likely your issue. If you try snaking it some way you could end up with a water leak in the wall as well. Good luck.
     
  8. Feb 11, 2013 #8

    Wuzzat?

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    Hopefully the junk in the pipe is much less tough than the wall of the pipe.
    Maybe you can attack the rust chemically but such a product may not be recommended for pipes carrying potable water.

    Speaking of rust, you may want to check for leaks before you start.
    With everything off in our house the water meter showed one gallon in three minutes escaping from a pinhole leak in a pipe under our slab.
     
  9. Feb 11, 2013 #9

    nealtw

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    Sorry I missread the first post. Change to a single lever from the front and use a plate that covers the old holes If you have 2" of access you can use pex and connect to the new copper you have available.

    single lever.jpg
     
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  10. Feb 13, 2013 #10

    frankflynn

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    I fear that you are right - that pipe is old enough. Snaking or a chemical treatment would be almost as difficult to administer - and as the other post suggests might cause a leak.

    This shower is on the second floor in the middle of the house so a leak is highly undesirable (as if they ever were desirable...).

    This weekend is a long one and I guess I'll be doing some demo and see what I got. The plumbing seems fairly straight forward (I've done more complicated projects with good results). But I've never built / rebuilt a shower. I might not need to rip it out fix the plumbing but I will have to rip a hole big enough to get to the pipes.

    I will take photos - I might post them if it's not a total disaster :)
     
  11. Feb 13, 2013 #11

    frankflynn

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    Good idea - I'm thinking though that I will have to rip the shower wall out because it is in a dormer and it is an outside wall.

    But I will measure carefully and if there is a way to do what you suggest I'm all for it.
     
  12. Feb 13, 2013 #12

    nealtw

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    Plumbers do it all the time, I've done it myself but I didn't have to change the feed pipes. Good luck.
     
  13. Feb 13, 2013 #13

    Fireguy5674

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    It appears from your original picture that your tub surround is fiberglass? Since you are trying to do minimum damage and save a major rebuild for later I would try something like nealtw suggests. You should be able to find a kit with a face plate that will cover your existing faucet holes and a single lever faucet. Get the kit first and determine the maximum hole size you can open to work through. With that and a combination of shark bite, pex and whatever else it takes you might be able to replace the pipe and shower valve. Yes it will be a less than pleasant task but it is usually possible.

    The other option I can think of is to cut a square hole large enough to work through and when you have corrected your plumbing problem repair the shower wall with fibergalss tape and resin. Then sand and paint the shower wall as a temporary fix till you are ready to redo the entire bath. I am sure there is some kind of paint that would hold up for a short time and make things look acceptable for the short term. Maybe an epoxy type paint?
     
    Last edited: Feb 13, 2013
  14. Feb 14, 2013 #14

    nealtw

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    I would be surprized if this couldn't be done with out further damage to the unit. Will have to enlarge the hole for the shower head to change the fitting up there, just keep the hole smaller than the cover plate.
     
  15. Feb 14, 2013 #15

    wilard

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    Nealtw is giving good advise

    I would tie into existing copper with shark bites
    And use swivel connectors at shower valve
    Be aware that if you have a tub shower unit you can't
    Use pex between the valve and tub diverter
     
  16. Feb 14, 2013 #16

    nealtw

    nealtw

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    wilard, welcome to the site. Is that a code thing, I wasn't aware.
     
  17. Feb 15, 2013 #17

    wilard

    wilard

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    If your referring to pex between valve and diverter

    The pex is narrower and creates a restriction sending the water up to the shower head
     
  18. Feb 15, 2013 #18

    nealtw

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    So you need full pressure at the head where you install a water saver.
     
  19. Feb 15, 2013 #19

    Fireguy5674

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    Neal I believe he is saying that the pex going to the tub spout is to small and causes some water flow at the shower head when the diverter is open.

    I have had problems with that happening. Not because of pex, but maybe because of restrictions at spout due to hard water build up. Never considered the spout issue. I figured it was at my valve.
     
  20. Feb 15, 2013 #20

    nealtw

    nealtw

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    There is no bathtub spout.
     

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