How to increase water pressure/flow in showerheads

Discussion in 'Shower & bathtub Forum & Blog' started by CindyJ, Feb 9, 2013.

  1. LLigetfa

    LLigetfa DIYer, not in the trades

    Messages:
    3,973
    Location:
    NW Ontario, Canada
    Most toilets do not rely on water pressure to flush, only gravity.

    Have you done the flow measurements into a bucket as I suggested? It is premature to talk about pipe size if the shower valve is the limiting factor. Pipe size affects pressure only relative to flow. Right now, I suspect the shower head is the limiting factor.

    Have you taken elevation into consideration? How much elevation difference is there between where the pump pressure switch is and where the shower head is? You can count on .43 PSI loss for every foot of elevation.
  2. jimbo

    jimbo Plumber

    Messages:
    8,997
    Location:
    San Diego
    Thank you for the feedback.... you do have the relatively uncommon, but the one situation ( low ph) where copper has problems. Doing a repipe with the relatively unflexible CPVC must have been a chore.
  3. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    21,995
    Location:
    New England
    FWIW, both CPVC and PEX have a lower flow capacity verses copper based on the same nominal size. This is because the outside of the pipe is what is controlled, not the inside, so because the plastic pipes need more strength, their walls are thicker, thus, the ID is smaller.

    What would have worked better was to have 3/4" pipe running to the shower, then converting to 1/2" (which is probably the valve's inlet size, although some are 3/4" or even larger). Most things can function fine on 1/2", but high flow or multiple fixtures off one line need a larger supply coming into the area, then branching off with smaller pipes, where appropriate. If they ran 1/2" to the bathroom group, you'll find a real issue if someone flushes the toilet or tries to run the vanity sink while you're in the shower!
  4. Hackneyplumbing

    Hackneyplumbing Homeowner

    Messages:
    66
    Location:
    Alabama
    I would rather see a static pressure of around 75psi and no higher than 80psi.
  5. LLigetfa

    LLigetfa DIYer, not in the trades

    Messages:
    3,973
    Location:
    NW Ontario, Canada
    With the pressure switch adjusted to 60/80 and a CSV properly dialed in, the OP could see just that.
  6. cacher_chick

    cacher_chick Test, Don't Guess!

    Messages:
    3,246
    Location:
    Land of Cheese
    40-60 does a fine job with the right shower head. I would speculate that the majority of homes in the U.S. have less than 60 psi.
  7. Hackneyplumbing

    Hackneyplumbing Homeowner

    Messages:
    66
    Location:
    Alabama
    Let a guy get use to 70-80 psi and cut it back to 40-60 and you'll have complaint after complaint.
  8. CindyJ

    CindyJ Member

    Messages:
    53
    Location:
    Pennsylvania
    Okay -- I did the "bucket test." I should mention that my husband has removed the flow restrictors on both the stationary and hand-held showerheads. I ran two tests. The first one ran at 2.3 GPM, the second one was 2.5 GPM. I'm guessing that the variation was due to the cycling of the pump pressure.

    So now my question is, is this more a matter of increasing the water pressure, or changing the CPVC from 1/2" to 3/4"? Or should we do both?
  9. CindyJ

    CindyJ Member

    Messages:
    53
    Location:
    Pennsylvania
    I went down to the basement and the good news is that there is 3/4" pipe running from the filter to various places in the house. Or maybe it's just news, not necessarily good news because I don't know the size of the original copper pipe that was replaced with CPVC. What is still unknown is where, exactly, the 1/2" is joined to the 3/4". I do know that both bathroom showers are served with 1/2" pipe from the same split source. That, alone, is probably cause for concern.

    I'm expecting my plumber here today and I'll certainly have a conversation with him about this.
  10. CindyJ

    CindyJ Member

    Messages:
    53
    Location:
    Pennsylvania
    When you say "static pressure," does that mean a consistent water pressure as opposed to water pressure that fluctuates when the pump turns on and off?
  11. CindyJ

    CindyJ Member

    Messages:
    53
    Location:
    Pennsylvania
    My plumber is here now and I've been discussing the pressure problem with him. He removed the Kohler Pressure Balancing Valve, took a close look at it and told me he doesn't see how an adequate supply of water could possibly flow through such small holes. I told him that that model has a 5.0 GPM flow rate and he's baffled. Could it really be that this valve is the source of the water flow problem? He does agree, BTW, that the 1/2" CPVC could be problematic, especially since it branches into two showers.
  12. CindyJ

    CindyJ Member

    Messages:
    53
    Location:
    Pennsylvania
    So when I asked the plumber (who is here right now) specifically about the reduced flow rate with CPVC, he said yes, it's less, but not so much that it would be noticeable. It's his assertion that it's the design of the showerhead, itself, even with the flow restrictor removed, that is responsible for the reduced pressure. And now I'm beginning to think that I don't really understand the distinction between reduced pressure and reduced water flow insofar as my experience with the shower is concerned. That is, I don't really know if it's that I'm feeling less water or less water pressure than I felt with the old showerhead and the old pipes.

    I also don't want to sound like I'm telling the plumber how to do his job, but hey, I'm paying for it and I want it done right.
  13. Hackneyplumbing

    Hackneyplumbing Homeowner

    Messages:
    66
    Location:
    Alabama
    Increase the system pressure at the well pump. No more than 80psi. Problem solved.
  14. LLigetfa

    LLigetfa DIYer, not in the trades

    Messages:
    3,973
    Location:
    NW Ontario, Canada
    +1 But you may need to consult a professional to ensure the system is capable of producing the higher pressure without deadheading the pump, that the bladder tank precharge is adjusted, and that the pump switch doesn't have a low pressure cutoff that could nuisance trip. Also, pump cycling should be evaluated and perhaps mitigated.
  15. LLigetfa

    LLigetfa DIYer, not in the trades

    Messages:
    3,973
    Location:
    NW Ontario, Canada
    Static pressure is simply the pressure that exists in the absence of flow. Resistance in the lines, valves, aerators, showerheads, etc., will all conspire to reduce the pressure under varying flow conditions.
  16. LLigetfa

    LLigetfa DIYer, not in the trades

    Messages:
    3,973
    Location:
    NW Ontario, Canada
    Is this the first mention of a filter?

    Filters can be flow restrictors so they too must be factored in. When there are disruptions to the plumbing system due to work that requires the system to be shutoff and drained, the subsequent in-rush can disturb sediment that used to lay dormant and this sediment can clog the filter and restrict flow with in turn restricts pressure.
  17. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    21,995
    Location:
    New England
    Ever notice the difference in the flow out of a hose when you offer a restriction? The water speeds up when you put your thumb over the end and sprays further. A showerhead does the same thing. But, now partially shut the valve, and while the pressure is exactly the same feeding things, the spray is no longer as intense. A valve that is flowing it's max and the shower head able to take all of that, isn't creating that speedup because there's no restriction. To get decent speedup, you have to be able to supply more water than the showerheads are designed for, otherewise, you'll get a feeble spray. that doesn't mean the showerheads will spray more, but that they will spray harder - there must be a restriction for the water to accellerate in the showerhead, and 5gpm in with (essentially) 5gpm out, there's no restriction in the line, thus no accelleration.
  18. CindyJ

    CindyJ Member

    Messages:
    53
    Location:
    Pennsylvania
    When I asked the plumber about increasing the system pressure from 40-60 PSI to 50-70 PSI he told me that the system would "blow" at 75, so increasing it wouldn't be a good idea. Part of what I'm up against is that I have no way of knowing if what he's telling me is correct and accurate.
  19. CindyJ

    CindyJ Member

    Messages:
    53
    Location:
    Pennsylvania
    Is the restriction you're referring to in the valve, or is it in the showerhead? I don't think there's anything that can be modified in the valve, and even with the restriction removed from the showerhead, the flow rate is still only about 2.5 GPM. Are you saying that that flow rate is okay because, as LLigetfa stated earlier, the valve is rated at 5 GPM? Or am I thoroughly confused?

    The reality is, what I really want is a "hard spray" -- I don't think it matters if it is the result of increased flow or increased pressure.
  20. LLigetfa

    LLigetfa DIYer, not in the trades

    Messages:
    3,973
    Location:
    NW Ontario, Canada
    Is that the flow through the showerhead? If you remove the showerhead how much flow do you get? If about the same, then the combined flow restriction of the valve and upstream piping is to blame.

    Ask you plumber what part of the system would "blow" at 75 PSI? It is not unusual for city pressure to be higher than that and most places code only call for a pressure regulator above 80 PSI.
Similar Threads: increase water
Forum Title Date
Shower & bathtub Forum & Blog Shower/Tub loses pressure as hot water temp increases Oct 21, 2010
Shower & bathtub Forum & Blog Shower pressure dropped and noise increased Jun 7, 2014
Shower & bathtub Forum & Blog How can I increase the temp of my Mix-it valve. Nov 16, 2008
Shower & bathtub Forum & Blog ok to increase number of turns in gal steel supply? Jul 23, 2006
Shower & bathtub Forum & Blog Waterproofing exterior deck over occupied space: How the deck build is a lot like a shower build Aug 27, 2014

Share This Page