Code Question for faucet handles

[Archsusie]

I would like to install a wall mounted shower/tub filler with two or three (with diverter) handles to control the water flow. The shower system that I am considering, Kingston Brass KBX8138NDL, does not come with a pressure balanced valve. As I understand the residential code regulations, water settings must be limited to 120F. I don't see how I can do this with any of the two handle systems. Any advice? I prefer the look of the two handle system to the large round balance pressure valve.

 

[Smooky]

You need a Thermostatic Mixing Valve at the hot water heater or in the hot line before it goes to that shower valve. If it is located at the shower, you need one that is approved for point of use, (the code might not allow an in-line thermostatic valve.) ... Sometimes people want the hot water to branch off to the kitchen sink, the dishwasher and the clothes washer and then install a whole house type of valve.


https://customer.honeywell.com/en-US/Pages/department.aspx?cat=HonECC Catalog&category=Thermostatic+Mixing+Valves&catpath=1.3.3.5

If you have a large enough hot water heater you could just set it at 120 degrees F and then a scald preventative valve would not be required.

Tempering valve for hot water to the tub. It takes hot and cold water and blends it down to a preset temperature.
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[Sponsor]

 

[Jadnashua]

There are also external pressure balance valves. The equation has two parts...limiting maximum hot available, and limiting spikes from pressure imbalances caused by say flushing a toilet, or some other (typically) cold water use which limits how much can temper your shower. There are also some valves that use two handles that have one handle controlling volume, and the second one the temperature.

 

[Archsusie]

Thank you. Very helpful replies. I have printed out and will pass on to plumber. I will check the temperature that the hot water heater is set at (but not sure that will satisfy the building inspector) or consider buying a thermostatic mixing valve for the hot water line at the tub.

 

[hj]

New code provisions are being discussed at this time about whether the thermostat is an adequate control for anti scalding, since stacking can cause the temperature at the top of the tank to be considerably higher than the thermostat setting.

 

[Jadnashua]

Where I live, you must have a tempering valve on the WH outlet, so regardless of the aquastat setting, you wouldn't pass an inspection without one. Achieving the anti-scald requirement on a shower with an old style, two valve mixing setup (two volume controls, hot/cold) requires some extra bits. By the time you build those extra parts in behind the wall, provide access for maintenance when they fail, most people, if they want to abide by the codes, opt for a valve with those features built-in. Most all of those can be serviced from the finished side. If the 'look' is more important to you, you then need to pay the piper to get it done 'right'. Personally, for a functional reason, I much prefer a thermostatically controlled valve - two handles, often concentric, but not always, one for on/off/volume, and the other for temperature control. Choose an 'old' style valve assembly, and you can make it code compliant, but it's a hassle.

 

[Reach4]

Where I live, you must have a tempering valve on the WH outlet,

What is the basis for that statement? Does your town have a special amendment to the plumbing code to that effect?

 

[Jadnashua]

What is the basis for that statement? Does your town have a special amendment to the plumbing code to that effect?

Yes... my Nashua, NH, local and state codes require both a tempering valve AND a vacuum relief valve on ANY WH installation to pass a plumbing inspection. NH uses IPC 2006 with amendments.

https://customer.honeywell.com/resources/techlit/TechLitDocuments/63-0000s/63-9481.pdf

 

[Smooky]

Yes... my Nashua, NH, local and state codes require both a tempering valve AND a vacuum relief valve on ANY WH installation to pass a plumbing inspection. NH uses IPC 2006 with amendments.

https://customer.honeywell.com/resources/techlit/TechLitDocuments/63-0000s/63-9481.pdf

I think they adopted the 2009 International Plumbing Code and forgot to mention it to you:
http://nashuanh.gov/275/Building-Safety-Department

The requirements for Individual shower valves has not changed though.

It does help if you are asking a code type question for the asker to provide what state/province you are in because the codes are different depending on your area.

 

[Reach4]

Yes... my Nashua, NH, local and state codes require both a tempering valve AND a vacuum relief valve on ANY WH installation to pass a plumbing inspection. NH uses IPC 2006 with amendments.

I did not see any requirement that "you must have a tempering valve on the WH outlet".

 

[Jadnashua]

This amendment pretty much requires it:
"Maximum temperature. Hot water not to exceed 130°F (55°C) shall be supplied at all plumbing fixtures and equipment utilized for bathing, washing, culinary purposes, cleaning, laundry or building maintenance. This provision shall not supersede the requirement for protective shower valves in accordance with Section P2708.3."

Since most any WH can be set to above this level, the only way to ensure that the system's outlet temperature is to provide a tempering valve. Also note that it precludes using that device to protect the shower.

http://www.nh.gov/safety/boardsandcommissions/bldgcode/documents/IRC2009NHAmendments.pdf

It's too easy in a shower for someone to end up injured without some anti-scald tech. 130-degrees max is way too hot for the average person if there's a distribution issue that allowed all-hot to intrude, a pressure-balance valve is the easiest way to satisfy that issue, and it must be at the point of use to do that to be effective. Usually, it's combined with a limit stop on how much hot can be supplied.

 

[Reach4]

Where does it say that "... you must have a tempering valve on the WH outlet"? Is there a place that says you cannot have your tempering valve 30 ft away or that you cannot have two separate tempering valves each 30 ft away from the WH in separate locations? That's the part that I felt you were being too creative with.

 

[Archsusie]

Thank you for making this clear to me. I am an architect, registered in New York, doing my first project in Washington DC. I am working with the 2012 International Codes (I-Codes) and 2013 DC codes. Section 424.3 states that individual shower and tub shower combination valves shall be balanced-pressure, thermostatic or combination......installed at point of use....and equipped with a means to limit the maximum setting of the valve to 120 degrees F. I will quit trying for a certain look and go to Home Depot and buy a round trim kit with a thermostatic valve.

 

[Jadnashua]

Where does it say that "... you must have a tempering valve on the WH outlet"? Is there a place that says you cannot have your tempering valve 30 ft away or that you cannot have two separate tempering valves each 30 ft away from the WH in separate locations? That's the part that I felt you were being too creative with.

It says that your outlet temperature cannot exceed 130-degrees...how do you enforce that without a tempering valve? While not specifically stated, from a functional viewpoint, the local inspectors require it as it's just too easy to tweak the thermostat on the WH. Yes, I know you can usually adjust the tempering valves themselves (and they usually come preset to about 120-degrees), but that's how they're interpreting it here where I live. But, even if your aquastat was set to 120-130, under some circumstances, you could have water MUCH hotter than that at the outlet of the WH, and to prevent that, again, a tempering valve would be required.

From a safety standpoint, except for a few uses, even 130-degree water is way hotter than necessary, but may be required to get the hot water volume you need, or to keep things from growing in your WH putting people's health at risk from other things than getting scalded.