Do thermostatic valves supply higher GPM than balanced pressure units?

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by Palladio, Jul 2, 2008.

  1. Palladio

    Palladio New Member

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    I am trying to decide on a new valve setup for my shower (shower head only, no tub or handspray). I am looking at several units from Harrington Brass.

    A sales rep in a local dealer said that thermostatic units generally supply more GPM than balanced pressure ones. Is this true?

    Also, do most thermostatic controls require a separate valve for volume contorol?
  2. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    I don't think there is a generic answer to this. A valve designed for 3/4" supply lines will generally be able to supply more than a 1/2" one. Unless you are using numerous showerheads, max volume is not the concern.

    Most thermostatic valves require two knobs or levers (or a combination); one for the temperature setting, and one for volume control. Pressure balanced valves typically only have one valve and turn on with max volume.
  3. Redwood

    Redwood Master Plumber

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    I feel for you... Nice foo-foo stuff... I charge through the nose to fix it!

    Sometimes, Maybe/maybe not

    No, Not all do.
  4. cattledog

    cattledog New Member

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    Palladio--

    U.S. Federal regulations (and energy saving common sense) limit max flow to 2.5 gpm from a showerhead, so gpm through the valve is really not an issue. In my experience a volume control is not really required with low flow shower heads as you will probably not be turning the volume down much. Some spray head units have several flow variations and often a lower "eco" setting which gives you an alternative way to turn down the volume. A pressure balanced temperture control at a fixed flow rate will cost less than a thermostatic unit with volume control, and it's really not too hard to move the handle to the right position when you turn on the shower.
  5. Redwood

    Redwood Master Plumber

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    The place where the high flow capacity valves come into play is with the loophole in the law. While each showerhead's flow is limited by the law...
    There is no law limiting the number of showerheads used in a shower.
    A pressure balanced mixer will hold a range of about +- 3 degrees, while a thermostatic mixer will do about +-1 degree.
  6. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    Those temperature variations are instantaneous, not over time. A thermostatically controlled valve will also keep the same temp as you run out of hot water until it is running full hot; handy if you are the last one in a string of users and the hot water is running out - it will maintain the temp until there isn't enough. Also, it will maintain the same setting winter and summer in the same position so it's just turn on the volume as the temp is always 'perfect' (unless someone messes with it in the interim!)
  7. Palladio

    Palladio New Member

    Messages:
    48
    Thanks for the helpful responses.

    A few clarifications and questions:

    I am mainly considering Harrington units because they would match the Harrington lavatory set I already have. If anyone has recommendations for other manufacturers who make antique or retro looking fixtures, I'm open to ideas.

    The pipes in my wall are 1/2", but the Harrington thermostatic units are mostly 3/4".

    I am keeping my ancient Speakman showerhead (probably 1930's) that I'm sure flows well over 2.5 gal per min. I know it is not the most environmentally conscious decision, but I have spent a small fortune on recycling water in my business. I am going to keep the luxury of a powerful shower as a small reward.

    Am I correct in assuming it's not a big deal to fit a 3/4" unit to a 1/2" pipe? Will the unit still function correctly?

    Since I am in an apartment building where hot water supply is not an issue, is there any point in going with thermostatic over pressure balanced? From what you've said here, it sound like the only advantage in my situation would be having the shower preset to a desired termperature.

    To use a thermostatic unit, do you simply turn on the separate volume control or do you you have to shut the thermostatic valve when you're turning the shower on/off.
  8. Palladio

    Palladio New Member

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  9. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    Location:
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    The temperature control and volume control are totally separate, so you can adjust them independently. They also keep the temp winter to summer when the cold incoming water temperature changes. Each time you turn on a pressure balanced valve, you have to hunt for your favorite temp, and that will change from winter to summer because the cold changes. Is this a big deal? No, is it nice - Yes!
  10. Redwood

    Redwood Master Plumber

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    My problem with what I refer to as Foo-Foo is that it is designer stuff...
    Is that all too often I get sent to a customers house to fix a malfunctioning shower mixer. Here is what I find...

    [​IMG]

    Do you see a name anywhere? I don't!
    No matter... Lets just pull it apart and see what is needed... Take the cartridge to a supply house and see if they can match it up... A common way of dealling with these...

    Hmmm the handle is off... The nut under the handle that looks like it holds the faceplate on is off... Yet the face plate won't budge... Looking for a set screw or locking clip I find nothing... I'm clueless how to get this apart... All I know is it probably costs more than I make in a week! I better not get too crazy and break something! I'm going to have to come back after I find out more about this valve.

    I go home that night and look on line I go to a bunch of sites looking at their products... Finally I find a couple that look close. I think it is either a Lefroy Brooks, Waterworks, or, Herbeau Creations. There is a Foo-Foo dealer about an hour and 15minutes away from here one-way that carries most of those and I send off an E-Mail with the picture I took before I left asking them If they know what it is, parts and possibly a parts break down so I know how it comes apart...

    A couple of days later I get the reply that it is a Harrington Brassworks Thermostatic Mixer. The cartridge if I remember right was about $450. They also sent a crude drawing of the valve and the parts... It looked like someone freehanded it with a ballpoint pen and made copies!

    At this point I already had about 5 hours into this job and I had yet to go back to fix it or drive to get the part!

    Go to the Harrington Brassworks website below and see if you can find any info on how to work on this valve, parts breakdown etc. You've got it easier than I did... At least you know it's a Harrington Brassworks mixer... Thats a lot more than I had to go on!

    http://www.harringtonbrassworks.com/indexF.html

    Yea, Put it in! It will break at some point. The one I had worked on had been fixed once before and was about 5 years old when I worked on it. There is nothing really special about it that will make it so it never breaks. Just don't complain about how much it costs to fix! It's not the plumbers fault you bought Foo-Foo Designer Crap!
    Last edited: Jul 4, 2008
  11. Palladio

    Palladio New Member

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    Redwood,
    I follow you on this. And yes that is indeed the Harrington unit I am considering. I do have the advantage of knowing what I'm installing, and if it breaks I don't need to waste 5 hours of a plumber's time to source parts.

    Elsewhere on this board someone said that Harrington uses Grohe supplied rough-ins. Anyone know if this is true? If so, the valves should be of decent quality.

    Just curious, what do you recommend that is not Foo-Foo? I am restoring a 1930's bathroom, so the usual Grohe, Moen, Delta is not going to look right for this application.

    The Harrington Brass line isn't cheap, but from what I've found, it's not exactly at the top end either. A thermostatic mixer and trim is around $600. Most of the "designer" stuff I've seen (such as Waterworks) is more expensive. I have yet to find a manufacturer of solid brass parts with polished nickel plate that are significantly cheaper.

    Not arguing with you here, but would like to know if you could recommend a brand that has an antique look that is not "foo foo" in your opinion.
    Last edited: Jul 4, 2008
  12. Redwood

    Redwood Master Plumber

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    Location:
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    Taking Delta & Moen out of the equation kinda really puts a damper on non Foo-Foo. That pretty much leaves Am. Std. (Junk), & Kohler (Parts PITA... might as well be Foo-Foo)...

    I never thought I'd say this but how about a more common Foo-Foo...
    Like Grohe?

    [​IMG]

    At least you can find a legible parts breakdown on the web that can be read.
  13. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,266
    Location:
    New England
    I've had a Grohe thermostatic valve installed now for about 5-years. I did recently take it apart and put some plumber's silicon grease in it, but it didn't leak and was still smooth in operation; now, it is easier to turn (not that it was all that hard).

    Last trip to London, the Holiday Inn Express had them in their showers, and you could really tell (from pressure variations, but not temp) that at times, there was a lot of people using water and the pressure was changing. A pressure balanced valve may have been able to keep up as well, but, the temp setting stayed the same for the week we were there, and worked great. I've got a local dealer that stocks most of the cartridges, but (bad me!) I did order the valves off the internet.
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