Model # 34397000

Internet #203014168

GROHE 3/4 in. Thermostatic Valve in Starlight Chrome


3/4 in. Thermostatic Valve in Starlight Chrome

  • GROHE TurboStat - Maintains water temperature for safety
$20024 /each
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Frequently Bought Together

Product Overview

GROHE thermostatic temperature control valves insure a maximum of bathing safety for everyone, but are particularly important for small children, physically disabled people, and elderly people. Due to GROHE Turbo Stat technology, our GROHE thermostatic valves are accurate to within 1 degrees Fahrenheit. Enjoy the perfect bath or shower by simply dialing your desired water temperature. A high-flow GROHE thermostat rough valve is perfectly suited and preferred for meeting the demands of large multiple-head custom shower systems. But GROHE thermostats, however, are not just muscle. They are available with a wide selection of trim options in multiple finishes to match or compliment GROHE faucet and shower designs.

  • GROHE TurboStat technology delivers water at a desired temperature within a fraction of a second and keeps it constant for the duration of the shower
  • Paraffin cartridge
  • NPT
  • Service stops
  • Built-in check valves
  • Temperature control only
  • Back-to-back installation, (34 331) and (34 397) only, by reversing the cartridge – No additional parts required

  •  grohe turbostat




Warranty / Certifications

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Customer Questions & Answers

If I have 3 body sprays, a rain shower head, and a main shower head, should i plumb it all off on...

If I have 3 body sprays, a rain shower head, and a main shower head, should i plumb it all off only the top or the bottom, or can i use both?
Asked by: ct
No, you just one to use one port and cap off the other . If you use both ports you can get a difference in temperature.
Answered by: Grohe Customer Care
Date published: 2017-05-11

Does this Thermostatic Valve require Volume control Valve? Or can I turn on and off the water flo...

Does this Thermostatic Valve require Volume control Valve? Or can I turn on and off the water flow with this single thermostatic valve?
Asked by: RageHot
Yes you need a volume control for each outlet of water the thermostat only controls the mixing of the water.
Answered by: Grohe Customer Care
Date published: 2017-03-01

This valve has 2 inputs (hot and cold) and 2 separate outputs (top and bottom), how do you determ...

This valve has 2 inputs (hot and cold) and 2 separate outputs (top and bottom), how do you determine which output top or bottom will be passing water through. If I needed to only use one top output can I just cap the bottom?
Asked by: RageHot
Yes, if your using one outlet you cap off the other
Answered by: Grohe Customer Care
Date published: 2017-03-01

grohe rough in valve compatibility

with atrio themostatic trim
Asked by: deb
Please use GrohFlex universal rough-in box #35026000 for following Atrio trims: - 19849000 - 19865000 - 19848000 For trim 19169000 please use following: - 34331000 - or 34397000 (Requires Twin Ell for shower/tub combinations with diverter tub spout)
Answered by: Grohe Product Expert
Date published: 2017-02-28
  • y_2017, m_7, d_17, h_1CST
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Customer Reviews

3/4 in. Thermostatic Valve in Starlight Chrome is rated 5.0 out of 5 by 1.
Rated 5 out of 5 by from An exceptional valve. Things for the homeowner and the installer to watch for: My wife and I run a small property business in western Pennsylvania. We buy, renovate, rent, and sell homes. I am the Pennsylvania-registered home improvement contractor of our outfit, and head up our small work crew. We have quite a bit of experience in bathroom renovation, from bare-bones functional overhauls to full luxury rehabs. This plumbing fixture is a 3/4 in. high-flow thermostatic shower valve. It is exclusively used with one outlet capped as the mixing valve for residential luxury showers. This is most definitely not a DIY sort of thing to install. Accordingly, this review has two parts: one that I hope will caution the end user about the pitfalls of installing such a valve, and one that I hope will help the installer plan well to put this particular valve in to a framed shower wall. For the end user/homeowner: The most important thing to mention is that this is a heavy-duty thermostatic valve. It’s big and beefy, and there’s a lot of brass that will have to corrode before this valve suffers a catastrophic failure. It should easily last a lifetime or two in the home and will most likely outlast the water piping that supplies it. A number of high-end GROHE trims will fit on it in one of this three configurations. Yet there are plenty of homeowners who buy something like this and don’t actually need it, because their setups dictate that they can’t actually get value for their money out of a 3/4-inch high-flow valve like this. There are two main pitfalls for the homeowner to avoid when investing in a high-flow valve like this: 1. Inadequate water supply to take full advantage of the high-flow qualities of the valve: Your water supply piping diameter has to be at least 3/4 in. from the main line leading into the residence all the way to the shower inlet for the cold water, and 3/4 all the way from the water heater outlet to the inlet for the hot water. It is much more common to see 1/2 in. water supply piping in almost any older home with copper water supply piping. You can’t add a 3/4 in. valve to 1/2 in. water supply piping and expect that you’re going to get more water flowing out of the same pipes just because you increased the diameter upstream. But I’ve seen it tried more than once for various reasons, so make sure it doesn’t happen to you. 2. Drainage: This is the really dangerous pitfall, and I’ve seen several negatives outcomes happen because of this (with one really tragic one), so I’m going to take it slow explaining the problem here. So... Your dream may be to build a luxury shower during a limited bathroom remodel in an older home. You might come to the decision to replace an existing walk-in shower with a slightly larger one, or maybe, you might decide to upgrade the water supply for your existing shower pan and surround and turn it into a high-flow luxury shower with multiple nozzles and showerheads all going at the same time. In either case, you’re starting with existing drainage infrastructrure. Typical building codes demand a drain that 1.5 inches in diameter for a tub, and two inches for a shower. The larger size for the shower is demanded because a shower pan can’t hold as much water as a tub, and there’s less time to react and turn off the running water if something goes very wrong. Again, we’re talking about an older home here. Let’s say that at some point the former owner of your home upgraded from the original tub that was in your bathroom to a walk-in shower with a rather nice shower base and surround that fit in much the same space as the old tub. This is a very common upgrade in flipped homes. A basic 60x30 in. tub is replaced with a 60x30/32/36 or 36 x 48 prefab shower base. Unfortunately, there have been plenty of cases where a 1 1/2 in. to 2 in. adapter coupling quietly ended up on the existing tub drainage as a quick-fix and the entire drainage system of the original tub back to the vertical waste stack wasn’t upgraded to 2-inch drainage piping. This in my experience happens most frequently out in the far tax-shelter suburbs of an urban area that are right over a county line. The suburban county’s health department often doesn’t require special plumbing permits, the owner wants to get out of his 80s-vintage McMansion quickly, the owner’s brother’s dealership sold the town police force all their vehicles at a reduced rate and perhaps a kickback...a variety of questionable renovations tend to happen in premium homes in those tax-shelter areas with limited code enforcement around here. Now along you come as a new owner, completely unaware of this history and you look at that shower with invisibly botched drainage and you decide you also want a limited upgrade on what’s already in place. You just want a nicer water supply system. So contractors run new 3/4 inch supply lines to your shower, replacing a showerhead that produced a regulated 2.5 gallons per minute with, say, a series of four body sprayers, a handshower, and a large raincan showerhead that all together max out at 15 gallons per minute. This valve can handle that much flow if your water supply can, so you “go for the max,” as it were. You’re really in for a lot of trouble if those gallons and gallons of water are only washing down a 1 1/2 in. drainpipe right after the P-trap. Ideally, your contractor would clearly explain that it would be wise to either install two 2-inch drains of a 3-inch drain in a shower like this, but in any case you the homeowner have to be absolutely sure your drainage system can handle all that water, especially if the shower is on an upper floor. That’s my review for the homeowner. This is a great, premium-quality valve engineered and manufactured to the highest standards and it will give full satisfaction, but it’s made to be part of a system, and the system will only be as good as its weakest part. For the installer: A lot of GROHE’s product line in the USA consists of slightly-altered copies of its European hardware. The higher up in the premium market you go, the less Americanized and more fully European this hardware is. This has both its bad and good point when it comes to specialized GROHE products as far up the premium ladder as this one. You will notice the obvious very quickly, that this thick-walled brass fixture is built like a tank compared with many of its competitors. Part of the reason for this is that so much bathroom hardware in European apartment and single-family buildings is not designed to go into platform-framed, hollow-wall construction. It is instead mostly intended to be in a masonry wall, possibly with acidic water leaking onto it leached out of bricks and poured concrete for decades. Corrosion from that source must be minimized and the lifespan of the fixture maximized. That explains the tank-like features of this valve. Pay careful attention to the schematic diagrams and don’t hesitate to call GROHE US customer service for help. I’ve had mostly good results working with them. Again, GROHE’s European roots means that the German engineering division is used to minimal written instructions and mostly diagrammatic help, since European Union laws mean that any product like this sold in Europe has to have any written directions translated into all the 24 official languages of the EU. You will notice very quickly that the valve itself has no anchor bracket designed to screw into blocking. GROHE has updated their Grohsafe 1/2 in. pressure-balance valves and their Grohflex cartridge system sold in the USA to have rear anchors points, but not this thermostatic line yet. You are going to have to do some serious strapping, and as you can see by the design, the valve is not well-suited for that. The valve is about 7 1/2 inches wide. If you go the traditionalist route and build this with water hammer arrestors sweated on the intakes it’s going to be tricky fitting the whole assembly into a standard 14.5 in. stud bay. Plan your framing and pipe layout accordingly. A cap for one of the outlets is not included. This is a rather silly oversight at this price point, but understandable given how infrequently this valve will be installed by DIYers and that convenience would be unnecessary. You would not normally install this sort of valve with an outlet to a diverter, even though you can. Normally, this would lead to three or more volume controls which would in turn lead to three or more fixtures in the shower. The idea of a luxury shower is total control; you can have every shower fixture going at once and adjust the volume of each to your satisfaction. A diverter would largely defeat that purpose. While the manual offers a rather tolerant range, it is exactly three inches from the back of the valve to the line on the plasterguard that should line up with the surface of the finished wall. This means you can’t simply strap it to a piece of 2x blocking screwed into the back of a 2x6 wetwall and be OK with a thin wall installation. Figuring out how deep to set the blocking is always part of doing a good thin wall or tiled shower, but with this valve you really need to set up that line properly and carefully and understand the depth issue well during your design phase. The 1/2 in. GrohSafe pressure-balance valve line has arrow-shaped plumb aids built into the plasterguard to help you keep that valve level. I’ve always felt those were silly. This thermostatic valve has a balance point for your level at the very end to help, and you can also balance your level on the top rim of the plasterguard. They are nice features designed to help professionals do a better job. The best part of installing this valve is that if you get it in correctly, you can have a high degree of confidence that it will stay where it is and do its job until the residence is bulldozed. This is a very good thing. The worst part is that it’s easy to do a bad job of putting it in. This is not such a bad thing.
Date published: 2017-06-25
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