bath hot water safety valve manufacturer

Building Quality Mixing Valves is what we do at Leonard. At the same time we offer the industries best Service. It starts with the Best Engineers, followed by the most technically knowledgeable Regional Sales Managers, topped off with the industries best Specification Reps. Our team of experts are easily accessible and have decades of market experience and knowledge on Mixing Valves and Mixing Valve Systems. Learn More

Every building is different and all manufacturers of mixing valves pipe recirculation uniquely. We have a video to help explain the basic design of a tempered recirculation system with a Master Mixer. This video will help the plumbing professional select the proper piping method for the job. Learn More

American Society of Sanitary Engineers publishes product standards of safety for plumbing systems.There are 5 major standards for mixing hot and cold water. Four of these standards are mentioned specifically in both the IPC and UPC Plumbing codes as well as the four states that use their own codes (California, Illinois, Wisconsin, and New Jersey).Commercial building require ASSE certified valves. Click below to understand how and when to use these valves. As always, you may contact a Leonard Sales/Engineering Specialist for assistance. Learn More

Our expert team of sales engineers can help you with all stages of your project — valve design & selection, plumbing & building code and specification assistance. Some of our professional installs are shown here. View Installs

Leonard Valve Shower Valves, many of which are expressly designed for institutions, are produced here in the United States and are made to comply with various standards proscribed by the ASSE.

In addition to Leonard cold/hot water mixing valves, we carry bath/shower combo valves, pressure-balanced exposed valves, single temperature valves, inline diverter valves, and others, many of which are ligature resistant.

Commercial buildings required ASSE-certified valves. Use only the best - Leonard Valves specifically comply with IPC and UPC codes as well as with the codes of the four states that prescribe their own (NJ, IL, CA, and WI).

All Delta tub and shower faucets are engineered to keep the water temperature within a safe ±3.6° F (±1.7° C)*. This technology makes sure your family doesn’t experience a sudden and possibly unsafe change in water temperature as a result of running water elsewhere, such as using a dishwasher, flushing a toilet or running a washing machine.

Delta thermostatic tub and shower faucets are built with TempAssure valves, while pressure balance tub and shower faucets are built with Delta Monitor valves. Both feature an adjustable handle limit stop that, when properly set, helps ensure the handle cannot be turned to a position that is too hot for comfort.

Anti-scald valves, also known as tempering valves and mixing valves, mix cold water in with outgoing hot water so that the hot water that leaves a fixture is not hot enough to scald a person.

Unwanted temperature fluctuations are an annoyance and a safety hazard. When a toilet is flushed, for instance, cold water flows into the toilet’s tank and lowers the pressure in the cold-water pipes. If someone is taking a shower, they will suddenly feel the water become hotter as less cold water is available to the shower valve. By the same principle, the shower water will become colder when someone in the house uses the hot-water faucet. This condition is exacerbated by plumbing that’s clogged, narrow, or installed in showers equipped with low-flow or multiple showerheads. A sudden burst of hot water can cause serious burns, particularly in young children, who have thinner skin than adults. Also, a startling thermal shock – hot or cold – may cause a person to fall in the shower as he or she scrambles on the slippery surface to adjust the water temperature. The elderly and physically challenged are at particular risk.

Anti-scald valves mitigate this danger by maintaining water temperature at a safe level, even as pressures fluctuate in water supply lines. They look similar to ordinary shower and tub valves and are equipped with a special diaphragm or piston mechanism that immediately balances the pressure of the hot- and cold-water inputs, limiting one or the other to keep the temperature within a range of several degrees. As a side effect, the use of an anti-scald valve increases the amount of available hot water, as it is drawn more slowly from the water heater. Inspectors and homeowners may want to check with the authority having jurisdiction (AHJ) to see if these safety measures are required in new construction in their area.

Installation of anti-scald valves is typically simple and inexpensive. Most models are installed in the hot-water line and require a cold-water feed. They also require a swing check valve on the cold-water feed line to prevent hot water from entering the cold-water system. They may be installed at the water heater to safeguard the plumbing for the whole building, or only at specific fixtures.

The actual temperature of the water that comes out of the fixture may be somewhat different than the target temperature set on the anti-scald valve. Such irregularities may be due to long, uninsulated plumbing lines or defects in the valve itself. Users may fine-tune the valve with a rotating mechanism that will allow the water to become hotter or colder, depending on which way it’s turned. Homeowners may contact an InterNACHI inspector or a qualified plumber if they have further questions or concerns.

In summary, anti-scald valves are used to reduce water temperature fluctuations that may otherwise inconvenience or harm unsuspecting building occupants.

If the water temperature is above what your local plumbing code allows (110° F or 120° F), remove the handle or take off the temperature knob and rotate the rotational limit stop as follows:

Turn the limit stop counterclockwise For every tooth the rotational limit stop is rotated counterclockwise, the maximum water temperature will decrease approximately 6° F. NOTE: If your water temperature is too cool, rotate the limit stop clockwise.

MAKE SURE COLD WATER FLOWS FROM THE VALVE FIRST. ALSO MAKE SURE THAT YOUR WATER (AT ITS HOTTEST FLOW) DOES NOT EXCEED THE TEMPERATURE ALLOWED (see steps 1-4 above).

Note: Consumer safety is our number one concern. If you do not have experience with plumbing repairs, we recommend that you contact a licensed plumber for tub/shower repairs.

Well, it could be Opposite Day. But it’s more likely that the water lines may have been connected in reverse. See, cold water should always come on first when you’re operating a Monitor valve. And then rotating the handle counter-clockwise should increase temperature. If that’s not the way things are happening, you may be able to correct the problem by "flipping" the pressure balancing cartridge, as shown in the diagram below.

Here are the steps to follow in reversing the operation of your faucet.Before you begin, make sure that you’ve shut off the water supply to the faucet.

Unscrew the bonnet nut. The bonnet nut is a large brass ring and should unscrew by hand. If it’s too tight to remove by hand, wrap a towel around the bonnet (to protect the finish) and unscrew it with a pair of channel locks. Make sure that the entire valve body does not start to rotate as you do this. Remove the bonnet nut.

Do not pry the valve cartridge out of the body with a screwdriver. Place the handle on the cartridge stem and rotate it counterclockwise approximately 1/4 turn after the stop has been contacted. Remove the handle. Grasp the brass stem in the center of the white plastic assembly and pull it directly out, away from the wall. The valve cartridge should slide out of the body.

Reinstall the cartridge after rotating the entire unit 180 degrees. Make sure that the raised plastic stop, marked HOT, is on the right side of the valve.

Some would blame mischievous water gremlins. But not us. We would theorize that mineral deposits have built up around the spool and sleeve (the part of the Scald-Guard pressure balance valve that blends the hot and cold water). And a buildup like that could interfere with the valve’s proper operation. To solve this problem, follow the steps below (based on your model).

NOTE: Unless both the hot and cold water supplies are turned on, the pressure balance valve will allow only a dribble of water to flow through the valve.

You mean, besides a godsend? A Scald-Guard valve is a Peerless® shower valve feature that keeps you and your family safe from dangerous water temperature fluctuations in your shower and bath. These fluctuations may occur when a toilet is flushed, or when an appliance (a dishwasher, say) is turned on at the same time the shower is being used. When set correctly, the Scald-Guard valve will maintain your water temperatures within a pleasing ±3° F range (when the inlet water temperature is set correctly).

The adjustable rotational limit stop found on Peerless® valves allows you to set a maximum hot water temperature for water flowing out of the tub/shower. When set correctly, this safety feature will ensure that the handle in your tub/shower faucet never rotates beyond the set level—resulting in a safe bathing temperature.

It may need to be readjusted if the inlet water temperatures change. For example, during the winter, the cold water temperature is colder than it is during the summer, which could result in varying outlet temperatures. Typical temperatures for a comfortable bath or shower range from 90° F to 110° F.

First, let’s review what the rotational limit stop does. This stop allows you to set a maximum temperature on the hot water flowing out of the tub/shower. When set correctly, this safety feature will ensure that the handle on your tub/shower faucet never goes beyond the set level, resulting in a safe bathing temperature.

The stop may need to be readjusted if the inlet water temperatures change. For example, during the winter, the cold water temperature is colder than it is during the summer. This could result in varying outlet temperatures. Typical temperatures for a comfortable bath or shower range from 90° F to 110° F.

Is this a problem everywhere else in your house, too? If not, then you may have a Peerless® pressure balance valve. This valve contains an adjustable Rotational Limit Stop: a small plastic device designed to reduce the risk of scalding. You may adjust the temperature yourself. Just follow these instructions on adjusting the Rotational Limit Stop.Let the water run until both hot and cold water is fully mixed.

If the water temperature is above what your local plumbing code allows (110° F or 120° F), remove the handle or take off the temperature knob and rotate the rotational limit stop as follows:

Turn the limit stop counterclockwise For every tooth the rotational limit stop is rotated counterclockwise, the maximum water temperature will decrease approximately 6° F. NOTE: If your water temperature is too cool, rotate the limit stop clockwise.

MAKE SURE COLD WATER FLOWS FROM THE VALVE FIRST. ALSO MAKE SURE THAT YOUR WATER (AT ITS HOTTEST FLOW) DOES NOT EXCEED THE TEMPERATURE ALLOWED (see steps 1-4 above).

According to industry standards, the maximum allowable temperature of water exiting the valve should not exceed 120 degrees Fahrenheit. (Temperature may vary in your area.)

After adjusting water temperature, place a thermometer in a plastic tumbler and hold the tumbler in the water stream to test the temperature. Do not test with hands or any body part.

If your water supply or temperature is unacceptable throughout your house, you probably need to adjust the temperature on your water heater. We recommend you follow the instructions of your water heater manufacturer. Typically, water heaters should be set in the "moderate" range, especially if you have small children.

Note: Consumer safety is our number one concern. If you do not have experience with plumbing repairs, we recommend that you contact a licensed plumber for tub/shower repairs.

In these hot water temperature control articles, we explain how to buy, install, adjust and inspect anti-scald equipment to prevent hot water burns. We explain what a mixing valve, tempering valve, or anti-scald valve is, where and why these valves are installed on hot water systems, and how they work.

Photo: a Sparco anti-scald valve or tempering valve installed at a hydronic heating boiler. Other texts refer to these safety controls as mixing valves or compensating valves or temperature compensating valves.

Anti-scald valves used with water heaters are also called tempering valves or mixing valves. An anti-scald valve mixes cold water in with the outgoing hot water (or regulates pressure, or uses another approach) to assure that hot water exiting a building fixture is at a temperature low enough to be safe.

In the sketch shown below, courtesy of Carson Dunlop Associates (found at page bottom, Click to Show or Hide), an anti-scald valve (also referred to as a tempering valve , a compensating valve or an automatic mixing valve) is shown installed at the hot water piping and tankless coil on a heating boiler.

The drawing illustrates that hot water leaving the tankless coil has been heated to 180 °F. by the coil which is itself immersed in hot boiler water. The 180 degree F. water leaving the tankless coil is mixed with 55 °F. water inside the tempering valve. This produces outgoing hot water from the valve cooled down to 140 deg F.

In the U.S., most authorities consider hot water at or below 120 deg F to be safe from scalding. Some facilities limit water temperatures to 100 deg. F.

Anti-scald valves typically are warranted for just 12 months from the date of installation. Plumbers report a typical tempering valve life of five years. (Moley 2022)

Really? We"re uncertain about how various plumbers or others have defined the service life of these plumbing components. For example, a bathtub faucet may begin to drip after 2-8 years but may need nothing more than replacement of a faucet washer: a part costing less than $1.00 U.S. and a job within the capacity of many homeowners and most handymen.

Some plumbing faucets and valves, such as models using a ceramic cartridge, may last the lifetime of the building even if the faucet"s finish and trim do not last that long.

Watch out: ease of replacement of faucet parts and even the cost of replacement faucet cartridges varies enormously. A typical brass Moen 1200 one-handle kitchen or bathroom faucet cartridge like the one shown above costs about $30. U.S. but we were quoted over $100. when trying to buy a ceramic faucet cartridge for a Kohler-brand bath sink faucet.

An anti-scald or mixing valve mixes cold water with the outgoing hot water either automatically or manually to make sure that a person using the plumbing fixture won"t be scalded.

and mixing valve manufacturers described here, all take care to refer to products like the Sparco control shown above and the Watts mixing valve shown on this page as a mixing valve or tempering valve. They are not promising that the device will prevent burns from scalding hot water.

That advice means that besides mixing valves or tempering valves that are typically installed at the water heater or tankless coil, separate anti-scald protection devices are available for and should be installed at the point of use: sink, shower, or tub etc. Those sorts of anti-scald devices are also discussed in this article.

Above, in our photograph of a more traditional single-function heating boiler limit control, the limit switch is being used on a tankless coil, serving as an upper limit on the temperature to which the boiler is to heat its water. This temperature may and usually is well above 120°F and so is a scalding burn hazard.

Really? In my experience with plumbing and heating installers, home inspectors, and consumers, these terms: automatic compensation valve, mixing valve, tempering valve, anti-scald device, automatic pressure regulating valve, pressure balancing valve, pressure compensating valve are thrown about in a blizzard of usages that treat the words as synonyms.

In the course of inspecting several thousand buildings between 1976 and 2014, I have almost never found anti-scald devices at individual plumbing fixtures in private homes. The only water temperature control we typically find are mixing valves at the hot water source. Worse, sometimes there is no hot water scald protection at all.

When a heating boiler uses a tankless coil to produce domestic hot water, a third single-function control may be installed for that purpose. In our photo, a Honeywell limit control switch is being used to monitor hot water temperature at the tankless coil which is in turn mounted on a steam boiler of an older home in Portland, Maine.

Cold water from the building is entering the tankless coil via the bottom pipe (green corrosion) and hot water, heated by the coil is leaving at the upper part of the tankless coil, where it turns downwards to enter the left side of the mixing valve.

Additional cold water is permitted to enter the bottom of the mixing valve, and tempered (non-scalding) hot water then leaves at the right side of the mixing valve in that photo,

Avoid scalding burns on someone using the plumbing appliance - generally by trying to prevent water temperature at the device from exceeding a safe limit either set by the manufacturer or adjusted by the installer or user.

Note that once a temperature limit or stop has been set, water temperature might still vary both above or below that setting, depending on the type of limiting device and on the causes of variation of water temperature entering the building or of hot water produced by and exiting the water heater itself.

Avoid or minimize variations in water temperature - generally by monitoring water pressure, flow-rate, or temperature to avoid surges of hot or cold water.

POS: Point of source: these controls are installed at the water heater or at the heating boiler that uses a tankless coil, as a tempering or mixing valve using any of several methods to control outgoing water temperature to the entire building, detailed below.

POU: Point of use: these hot water temperature controls are installed at or close to the point of use or individual plumbing fixture as we detail below.

THERMOSTATIC HOT WATER TEMPERATURE CONTROL at POINT OF USE -or POS - point of source for some devices including TAFR - Temperature Actuated Flow Reduction devices as well as others.

Watch out: as you"ll read here and in the article topics we have listed, various water temperature control devices have different purposes, and not all of them are designed to prevent scalding burns.

Watch out:Where no anti-scald valve is installed, the risk of a person being badly burned by hot water can be significant in buildings for a variety of reasons that we will explain here, including:

Use of water use efficiency improvement devices such as low-flow shower heads. When a low-flow-rate shower head is retrofitted to a home where no anti-scald valve or automatic compensation valve has been installed, even if the shower controls or tub controls have been manually adjusted to provide safe comfortable water temperature, the unexpected use of other appliances or plumbing fixtures in the building can cause the water temperature at the shower or tub to suddenly become scalding.

Watch out: it can be confusing listening to plumbers, home inspectors, and building supply sales staff who toss around terms like "mixing valve", "tempering valve", and "pressure-balancing valve" a bit loosely, all referring to ways to avoid scalding burns at plumbing fixtures, but not all working the same way.

Watch out: every anti-scald device, mixing valve, temperature control device whose instructions we reviewed includes a collection of safety warnings that explain the limitations of the device and its vulnerability to improper installation, improper adjustment, or to external causes of water temperature variation that are outside the scope of the control.

Watch out: read the installation instructions from the manufacturer of the product you are installing, both to make sure it"s installed properly and thus will work as expected, and also so that you understand what to expect by way of hot water temperature control that the product handles.

WARNING: Thermostatic mixing valves are intended to increase the supply of hot water available from the coil. They are not intended to prevent a scald hazard.

Similarly, the Watts Regulator Company"s instructions for the installation of the Series LF1170 & LFL 1170 Hot Water Temperature Control Valves includes this warning: [Bold font is our emphasis]

The first document below lists the components and parts of the mixing valve you describe - or a model close to it. The second provides instructions for a newer Thermostatic Mixing Valve or TMV from Danfoss, the Series 30 HR/HV.

Products listed here include thermostatic mixing valves of several types including valves that are installed at the fixture or point of use (POU thermostatic mixing valves), valves that are installed at the water heating source, and other products.

Watch out: as you will read in the individual product specifications, some thermostatic mixing valve instructions take care to mention that the valve does NOT provide scald protection and should not be used where ASSE 1070 devices are required.

Apollo DUAL PURPOSE THERMOSTATIC MIXING VALVE IO MANUAL [PDF] Model MVB & MVBLF ASSE 1017 Point-of-source & ASSE 1017 Point-of-use, Conbraco Industries Inc., 1418 Pearl St., Pageland SC 29728 USA Tel: 704-841-6000

Apollo THERMOSTATIC MIXING VALVE 34ALF Series SPECIFICATIONS [PDF] Apollo, Op. Cit., this valve is a POS or Point of Source use only temperature control valve.

The Apollo “MVB” Series are designed to mix and regulate the amount of cold and hot water to produce a comfortable and safe outlet temperature at a predetermined setting, either from the “point of source” or “point of use” application for single or multiple fixtures.

ASSE 1017 model 5231 series high flow thermostatic mixing valves are designed to be installed at the hot water heater (point of distribution) and cannot be used for tempering water temperature at fixtures as a point-of- use valve.

Series 5231 thermostatic mixing valves can also be used for regulating the flow temperature in radiant panel heating systems, to which it assures a constant and accurate control with ease of installation.

Cash Acme HEATGUARD 110-D SERIES TEMPERATURE-ACTUATED MIXING VALVE [PDF] (2014) assists in scald prevention, Cash Acme Corp., 2400 7th Avenue S.W. · Cullman · Alabama 35055 · USA · www.cashacme.com

Danfoss ESBE Series 20 THERMOSTATIC MIXING VALVE TMV INSTRUCTIONS [PDF] retrieved 2017/04/03, original source: http://na.heating.danfoss.com/PCMPDF/ESBE_Series20_TMV_instructions.pdf

Danfoss THERMOSTATIC MIXING VALVE Series 30 HR/HV INSTALLATION & MAINTENANCE INSTRUCTIONS [PDF] retrieved 2017/04/03, original source: http://na.heating.danfoss.com/PCMPDF/ESBE_HRHV_TMV_instructions.pdf

Photo: a replacement Delta Scald Guard cartridge. This is a rotational stop device. Detailed instructions on how to adjust this Delta scald guard device are given just below as a PDF download from the company.

ASSE compliance: ASSE 1017 - requires installation of a check valve. An expansion tank must be installed with the check valve to accomodate thermal expansion.

The AMX300 Series DirectConnect™ Mixing Valves fit any application requiring accurate control of water temperature by mixing hot and cold water such as domestic water.

KOHLER THERMOSTATIC MIXING VALVE INSTALLATION & CARE GUIDE [PDF] (2015) describing a POU point-of-use hot water temperature control from Kohler, Models K-2972, K2975, K2973, K2976.This valve meets or exceeds ASME A112.18.1/CSA B125.1 and ASSE

TUB AND SHOWER VALVES INSTALLATION INSTRUCTIONS [PDF] (2002) Moen, retrieved 2022/06/12, original source: https://assets.moen.com/shared/docs/instruction-sheets/mt692c.pdf

Moen, ONE HANDLE TUB/SHOWER VALVE TRIM INSTALLATION INSTRUCTIONS (2014) Moen, retrieved 2022/06/12, original source: https://assets.moen.com/shared/docs/instruction-sheets/ins2153c.pdf

Moley, Hot Water Tempering Valve, Maintaining & Servicing, [Website] Moley Plumbing & Gasfitting, retrieved 2022/06/12, original source: https://www.moyleplumbing.com.au/blog/hot-water-tempering-valve-maintenance-service#:~:text=A tempering valve should last approximately five (5) years.

Resideo (Honeywell) Braukmann PROPORTIONAL THERMOSTATIC MIXING VALVE [PDF] (2020) AM-1 1070 Series Proportional Thermostatic Mixing Valve, Resideo Technologies, Inc., 1985 Douglas Drive North, Golden Valley, MN 55422 1-800-468-1502

Symmons TEMPCONTROL 700-Series MIXING VALVE INSTALLATION MANUAL [PDF] [Shown above] Symmons Industries, Inc., 31 Brooks Drive, Braintree, MA 02184 USA, Tel: (800) 796-6667 Web: symmons.com Email: gethelp@symmons.com

left. Install retaining nut back onto valve body.[Note the requirement t torque the retaining nut to 132 inch pounds. - Ed.]5) Refer to "Setting Valve Temperature" section (pg.4)

Tempress PRESSURE BALANCING VALVE I-595 INSTALLATION INSTRUCTIONS [PDF] (2020) for use with Tub and Shower Fittings, Newport Brass, 2001 Carnegie Ave, Santa Ana CA 92705 USA Tel: (949) 417-5207

Watts, SERIES LF1170 AND LFL1170 HOT WATER TEMPERATURE CONTROL VALVE INSTRUCTIONS [PDF] (2013) Watts Regulator Co., USA Tel: (978) 688-1811, Fax: (978) 794-1848,

I can but guess because there is other information about your plumbing system that I don"t know, but it"s possible that you are anti scald device is installed at the water heater and that there is too much distance between that point and the nearest hot water Plumbing fixture.

A solution would be to install the anti scald device right at your plumbing fixtures. It"s more expensive in the landlord may not want to do that. OR the mixing valve output temperature is simply set lower than necessary. Temperature can be set as high as 120F. but no higher at the fixture or there"d be a scalding burn hazard.

A mixing or equalizer valve was just installed on my hit water tank by the landlord. I am finding that the water isn"t hot enough for us. We were told the temperature would be set for 110°F and would not be allowed to be higher.

We also pay for our own hot water usage through the gas company and it isn"t being paid for by the landlord. We are not using any cold water for showers or for anything other than drinking at this point. I would like to know if there is a way to increase the amount of hot water.

There is no risk of scalding in this house as we are adults who know how to live responsibly while using the water without harm to ourselves and others within the home.

If we are talking about a domestic water heater that produces hot water for washing and bathing, there will be a thermostat (or two of them) on the water heater; the thermostat controls vary depending on whether the heater is fueled by oil or gas or electricity.

Continue reading at ANTI-SCALD WATER TEMPERATURE CONTROL TYPES or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

ANTI SCALD VALVES / MIXING VALVES at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

Note: appearance of your Comment below may be delayed: if your comment contains an image, photograph, web link, or text that looks to the software as if it might be a web link, your posting will appear after it has been approved by a moderator. Apologies for the delay.

Thanks to Bruce Jones, Renewable Energy Solutions Manager, for suggesting clarifications about which way to turn the mixing valve to make water supply hotter or colder. email August 2010.

Thanks to reader Chris Martino for pointing out inconsistent text about which way to turn the hot water mixing valve or tempering valve. December 2010.

[5] "Water Saving Tips: For Residential Water Use, Indoors and Out",Alliance for Water Efficiency, 300 W Adams Street, Suite 601 Chicago, Illinois 60606, Tel: 773-360-5100, 866-730-A4WE, Email: jeffrey@a4we.org, web search 12/14/11, original source: plumbingefficiencyresearchcoalition.org/

[6] "Danger in the Shower: 2008 Forum Looks at Hot Water", John Koeller, Home Energy, Jan/Feb 2009, Home Energy Magazine, 1250 Addison Street Suite 211B, Berkeley, Ca. 94702, Tel: (510) 524-5405 Email: contact@homeenergy.org

TECHNICAL REFERENCE GUIDE to manufacturer"s model and serial number information for heating and cooling equipment, useful for determining the age of heating boilers, furnaces, water heaters is provided by Carson Dunlop Weldon & Associates

Your shower faucet and shower valve go hand-in-hand, and so it’s important to properly identify the type of faucet and the valve you own before replacing or repairing your shower system. Although the best way to identify the shower valve type is to speak with a plumber, the following steps can give you some clues on what shower valve type you currently own.

A three-handle faucet controls both the hot and cold water along, and a diverter handle shifts water flow between the showerhead, other shower attachments, or a tub.

A mounted showerhead, or fixed showerhead, directly connects to the shower pipe in the wall. It’s a stationary showerhead faucet that you may or may not be able to adjust the water flow angle on.

To identify the manufacturer of your existing valve, check the center of the trim plate for a logo or letter indicating who it’s made by—K for Kohler, M for Moen, though some brands have their full name on their trim.

Also, certain valves within each brand may require a specific kind of trim, so it’s important to check the manufacturer and the type of faucet you have or want.

Do not try to mix and match with manufacturers when it comes to shower faucet and valve parts. The different brands’ faucet and valve types and sizes are not interchangeable.

Scalding hot water from fixture faucets and fittings accounts for more than 25 percent of all scald burns in children. The elderly and the physically impaired also are at increased risk of scald burns because they have thinner skin and slower reactions. They often cannot recognize a hazard and get out of harm’s way before a serious burn can occur.

I have always said, “Scald burns and Legionella bacteria growth in hot water systems, which can lead to Legionnaires’ disease, are 100 percent preventable.”

Scalding and Legionella bacteria can be controlled when domestic hot water systems are designed, installed and maintained to keep hot water storage and distribution temperatures above the maximum Legionella growth temperature of 122 F.

Appropriate temperature controls must be used at or near fixtures to reduce the maximum hot water delivery temperature from fixtures to 120 F or below.

The attempt to prevent scalding and thermal shock injuries which often lead to slip and fall injuries was the driving force that brought about the invention of temperature control devices. In 1924, a plumbing manufacturer developed the first shower valve with a pressure-compensating element to address thermal shock common in two-handled shower valves.

Shower faucets before then typically had two-handled faucets that allowed the water from the hot and cold-water system to be mixed in a mixing chamber. A two-handled faucet or shower valve would have sudden changes in temperature as other fixtures were used in the plumbing system, which caused pressure disturbances that, in turn, caused sudden changes in temperature — either hot or cold.

The two-handled design provided the opportunity for a bather to receive serious scald injuries if someone accidentally turned off the cold water first while bathing or showering, which would leave only the hot water flowing to the shower. The original design had a pressure-balancing piston to adjust for thermal shock.

A couple of decades after the introduction of the pressure-balancing shower valve, newer designs of the valves entered the market. Other manufacturers developed additional safety components for shower valves, which included a maximum temperature limit-stop adjustment.

The limit stop adjustment allowed a single-handle valve to be manufactured and installed with a field-adjustable maximum temperature setting to a temperature at or below 120 F. The single-handle opened to the cold-water flow first and, as the handle was rotated farther, the valve added more hot water.

Hot water is often stored at or around 140 F, which was, and still is, the basis for water heater storage temperatures in many manufacturers’ equipment sizing calculations.

In uncirculated hot water tanks, the stored hot water temperatures could rise significantly above 140 F due to thermal layering (heat rising to the top of an uncirculated water heater).

Another phenomenon that causes the hot water temperatures to rise significantly above the water heater thermostat set-point is stacking. It occurs when there are multiple, intermittent, short draws of hot water from a water heater, causing cold water to enter the bottom of the hot water tank. The thermostatic element senses the cold water and turns on the burner, even when the water at the top of the water heater is well above the thermostat setting.

The ASSE Product Performance Standards for these devices are: ASSE 1016/ASME A112.1016-2011/CSA B125.16-11, Performance Requirements for Automatic Compensating Valves for Individual Showers and Tub/Shower Combinations; ASSE 1017, Performance Requirements for Temperature Actuated Mixing Valves for Hot Water Distribution Systems; ASSE 1062, Performance Requirements for Temperature Actuated Flow Reduction (TAFR) Valves for Individual Fixture Fittings; ASSE 1066, Performance Requirements for Individual Pressure Balancing In-Line Valves for Individual Fixture Fittings; ASSE 1069, Performance Requirements for Automatic Temperature Control Mixing Valves; ASSE 1070/ASME A112.1070-2015/CSA B125.70-15, Performance Requirements for Water Temperature Limiting Devices; ASSE 1071, Performance Requirements for Temperature Actuated Mixing Valves for Plumbed Emergency Equipment; ASSE 1082, Water Heaters with Integral Temperature Controls for Distribution Systems. (Currently finalized, awaiting board approval as of this writing.); ASSE 1084, Water Heaters with Integral Temperature Controls for Point-of-Use Applications. (Currently finalized, awaiting board approval as of this writing.); ASSE 1085, Water Heaters with Integral Temperature Controls for Use with Emergency Fixtures. (Currently under development as of this writing.)

In some applications, installing the wrong device or installing the device in the wrong location can lead to potentially serious scalding situations, thus exposing the end user to potentially scalding hot water temperatures. Furthermore, installing the wrong device can lead to a false sense of security by the ultimate user. Therefore, it is extremely important to make sure installation of the proper device is in the proper location. It must be maintained in accordance with the manufacturer’s installation and maintenance instructions.

Shower and Tub/Shower Combination Valves (ASSE 1016). Shower valves that comply with ASSE 1016 are automatic temperature and/or pressure-compensating valves intended to be installed at an individual shower or tub/shower combination fixture.

The model plumbing codes require all shower and tub/shower fixtures to have temperature controls that comply with ASSE 1016-2011/ASME A112.1016-2011/CSA B125.16-11, Performance Requirements for Automatic Compensating Valves for Individual Showers and Tub/Shower Combinations.

These devices are intended to control the water temperature to wall-mounted or ceiling-mounted hand-held showers; showerheads; body sprays, either in the individual shower or tub/shower combination fittings; and tub spouts, when part of tub/shower combination fittings.

There are three different types of shower valves meeting this standard: pressure-balancing, thermostatic (mechanical and electronic) and combination pressure balancing and thermostatic.

The showerhead flow rate must not be less than the manufacturer’s published minimum flow rate for the valve (device). The temperature limit stop must be set at the time of installation and may need to be periodically adjusted for variations in water temperatures. These devices provide both scald and thermal shock protection.

Temperature-actuated mixing valves for hot water distribution systems are used for controlling in-line water temperatures in domestic hot water systems to a relatively uniform temperature.

These valves should comply with ASSE 1017, Performance Requirements for Temperature Actuated Mixing Valves for Hot Water Distribution Systems or a comparable CSA standard listed in the code. When used, installation of these devices should be at or near the outlet of the hot water source only.

These valves are designed to provide a relatively uniform water temperature to the hot water distribution system, which makes setting maximum temperature limit stops in the system more reliable than a system without a mixing valve where uncirculated water heater discharge temperatures can vary by more than 30 F greater, or 15 degrees less, than the water heater thermostat set-point.

ASSE temperature-actuated mixing valves allow the water to be stored and distributed at higher, more stable temperatures, extending the amount of hot water available and also reducing the chance of Legionella bacteria growth in the tank and distribution piping. (See ASHRAE 188 and ASHRAE Guideline 12.)

These valves are not intended for point-of-use applications because of the large temperature variation. Valves must be sized to match the flow requirements of the system and not sized based on the pipe size (see Table 1). Further mixing downstream is allowed to provide final temperature control to protect against scalding. These devices used alone do not provide thermal shock protection or adequate scald protection.

To prohibit the cross-flow of hot or cold water through the valve, supplementary check valves should be installed for devices that do not include integral check valves by the manufacturer.

Temperature-actuated, flow reduction (TAFR) valves, when used, should be installed on the discharge outlet of the fixture fitting or integrated into fixture fittings.

These valves must comply with ASSE 1062-2006, Performance Requirements for Temperature Actuated Flow Reduction (TAFR) Valves for Individual Fixture Fittings.

They are intended for use in-line with, or integrated into, individual plumbing supply fittings such as showerheads, bathtubs, whirlpool bathtubs, utility sink faucets, kitchen sinks and lavatory faucets.

They are designed to automatically reduce flow down to a trickle within five seconds of outlet temperatures greater than a preset actuation temperature not to exceed 120 F (48.9 C). During the five-second response period, the bather may be exposed to temperatures more than the setpoint of the device.

These devices can be used on existing fixtures such as the showerhead associated with an older-style two-handle, nonpressure or temperature-compensating shower valve to provide scald protection. Typically, a TAFR device is used in an existing installation where no other form of scald protection is provided.

TAFR valves are not intended to be installed in place of devices complying with ASSE 1016, ASSE 1017, ASSE 1066, ASSE 1069 or ASSE 1070. These devices provide an additional level of scald protection only and do not provide thermal shock protection.

Caution: These valves automatically reduce discharge flow to a trickle if water temperature exceeds a preset limit. This trickle can be as much as 0.25 gallons per minute (0.95 L/m). When this device is installed on a bathtub spout and the outlet temperature exceeds the preset limit, and if the bathtub drain is closed, the bathtub could fill with extremely hot water from this allowable trickle.

Automatic pressure-balancing in-line valves are used to equalize incoming hot and cold-water line pressures. This minimizes mixed water temperature variations due to pressure fluctuations when used in conjunction with a mixing valve or two-handle valve set.

These valves must comply with ASSE 1066, Performance Requirements for Individual Pressure Balancing In-Line Valves for Individual Fixture Fittings. They are not designed to limit the maximum outlet temperature at the point-of-use. These devices provide thermal shock protection for pressure disturbances only and do not provide scald protection if the incoming hot or cold-water temperature changes.

Water temperature-limiting devices are intended to limit the hot or tempered water temperature supplied to fittings for fixtures such as sinks, lavatories, bidets or bathtubs to reduce the risk of scalding.

These devices must comply with ASSE 1070-2015/ASME A112.1070-2015/CSA B125.70-15, Performance Requirements for Water Temperature Limiting Devices. They are intended to supply hot or tempered water to plumbing fixture fittings or be integral with plumbing fixture fittings supplying hot or tempered water.

These devices have an integral water temperature-limiting capability. The user control allows the outlet temperature to be adjusted up to a maximum temperature of 120 F (49 C). They provide scald protection only and do not provide thermal shock protection.

Temperature-actuated mixing valves are intended to be used as a component to provide tepid water for emergency eye wash, eye wash/shower, drench showers and combination units that comply with the requirements of ANSI Z358.1.

These valves must comply with ASSE 1071-2012, Performance Requirements for Temperature Actuated Mixing Valves for Plumbed Emergency Equipment. These valves, by themselves, do not meet the requirements of ANSI Z358.1.

They consist of a hot water inlet, a cold-water inlet, a mixed water outlet, a temperature controlling element and a means for adjusting the mixed water outlet temperature while in service. These valves also have the means to limit the maximum outlet temperature under normal operating conditions.

Provisions shall be made so that the temperature cannot be inadvertently adjusted. These valves shall include a means of preventing cross-flow. Ideally, these devices are intended to be installed as close as possible to the plumbed emergency equipment. These valves provide scald protection only and do not provide thermal shock protection. They provide cold water bypass flow in the event of hot water failure.

Note: ASSE 1071 devices should be installed at individual fixtures. Emergency plumbed equipment must be flushed frequently, per industry standards, or per the water management or water safety plan to minimize stagnant water.