The title above is a strong, albeit true, statement. Burns caused by hot water delivered by your plumbing system are easily and absolutely preventable.
With today’s plumbing science and technology, product standards and development, and plenty of experience, scald burns should be a thing of the past. But, in reality, they are not. And you know why – it’s mostly human error, or ego, or not reading and understanding the manufacturer’s instructions until after something has gone wrong.
I know that I am “preaching to the choir” for the most part, since most everyone that will take the time to read this are well trained and informed plumbers, not just hacks who think they’re plumbers because they can put two pieces of pipe together or install a faucet.
The scariest potential causes of scalding issues are misconceptions and misinformation. How many of you have heard a reporter or safety advocate, or maybe even an unknowing plumber, boldly say, “Turn the thermostat on your water heater down to 120 degrees to prevent the potential for scalding hot water?” What a pile of bull. The key word here is “prevent.” More on this later.
Many of the water temperature limiting devices on the market today have been around for decades. Those that have been installed by a knowledgeable, licensed professional plumber have undoubtedly prevented many potential scald burns. But then you have those devices that have been installed by a plumbing installer (not a plumber, just someone who has some mechanical abilities), or a do-it-yourselfer, or a bathroom remodeler who does it all. Or maybe the product has never been tested to a performance standard. In many cases, the product installed to solve a water temperature problem is not the correct product for that particular application.
These scary truths were the driving force behind the 2009 formation of the ASSE Scald Awareness Task Group. The purpose of this task group is to raise awareness of the potential hazards of scald burns relating to plumbing systems and to educate the plumbing industry, along with the general public, on how to avoid these hazards.
Before the first task group was assembled, we needed to have a specific topic to work on. We asked the ASSE Board of Directors, and others who were interested in helping with the project, for suggestions. The first list contained about 15 ideas, many of which were eliminated for various reasons (e.g. code issues, design/engineering issues, etc.). We thought the best ideas to begin with were:
- Choosing incorrect products for applications;
- Incomplete or improper installation;
- How systems are effected when something is added or changed;
- Using water heater controls to maintain system temperature; and
- The effects of water saving devices
This Scald Awareness Task Group has published four white papers to date covering some of the above concerns. Each paper outlines and discusses a very common problem or misconception, and then details the solution to the problem with supporting data. Each task group is different, assembled through a call for participants, and each group represents all aspects of the industry – inspectors, plumbers, engineers, building officials, manufacturers, instructors, testing laboratories, labor officials, general interest, and safety advocates.
Our first paper, Scald Hazards Associated with Low Flow Showerheads, was published in Sept. 2010. This whitepaper discussed the increased risk of scalding and thermal shock associated with low-flow showerheads used in conjunction with non-automatic compensating type shower valves and tub/shower valves in older homes and buildings. Non-automatic compensating type shower and tub/shower valves are valves that do not compensate for sudden changes in incoming pressures and/or temperatures. These are generally the traditional two or three handle type shower and tub/shower valves with a cold water handle to the right and a hot water handle to the left. There are also some models of single handle shower valves that are not automatic compensating type shower valves.
Even with an automatic-compensating type shower or tub/shower combination valve, the flow rate of the showerhead should match, or be higher than, the flow rate of the valve.
With concerns for water conservation, many utilities have distributed low-flow showerheads at no cost to homeowners with the idea of saving water and associated utility costs. This is a great example of the unintended consequences of a good idea that was not fully thought out. Replacing a showerhead is a simple matter that does not require a homeowner to call a licensed plumber. However, when that homeowner or uneducated installer (I intentionally did not say plumber) installs that low-flow showerhead and does not know what effect it has on the system, a potential scald situation is created.
A brochure was developed with this paper and is available by contacting the ASSE International office. The entire white paper can be viewed and downloaded at www.asse-plumbing.org/downloads/ScaldHazards.pdf.
For our next project, we decided to undo the myth that the water heater thermostat can control the temperature of the hot water system by publishing Understanding Potential Water Heater Scald Hazards in May 2012. Model codes and many water heater manufacturers’ installation instructions state that the water heater thermostat should never be used to control the final water temperature at the point of use.
Many people have the misconception that the water heater thermostatic control is capable of delivering a constant, consistent water temperature. This paper addresses why this misconception can create a false sense of security and, more importantly, details how scalding and thermal shock can be avoided, and how to control the final point of use temperature.
There are many safety advocates out there who promote the idea of turning down the water heater thermostat to prevent scald injuries. While this idea may help reduce the risk of scald injuries, it does not solve the problem.
Water heaters alone cannot accurately control the hot water temperature at the point-of-use. For example, without specific technical knowledge of how the water heater operates and a failure to review operating instructions, the installer and consumer may assume that the water heater can control the water temperature with the same precision as a thermostat for a heating and air conditioning system at home. This misconception has led many users and operators to set their water heater thermostatic control at 120 degrees Fahrenheit and incorrectly assume that the water temperature will not exceed this value.
Thanks to advancements in water temperature limiting technologies, along with simple common sense practices and devices that are installed and maintained properly, scald injuries can be prevented by following these simple guidelines:
- Be aware: understand the risks of scald injuries;
- Be proactive: always test the water temperature before showering or bathing, especially if you are a care giver for a young child or elderly person who requires assistance; and
- Be responsible: install and maintain the proper temperature limiting devices at the point of use
Along with this paper, the task group developed a brochure that highlights the main concerns outlined in the paper. The entire white paper can be viewed and downloaded at www.asse-plumbing.org/downloads/WaterHeaterScaldHazards.pdf.
Another handy tool is Tommy Temperature, a turtle thermometer developed to test shower or bathing water temperature before a child’s bath time. Contact the ASSE International office for copies of the brochure or for Tommy Temperature thermometers.
Our third paper, Adjustment of Automatic Compensating Valves to Prevent Potential Scald Hazards, was completed in April 2015. This white paper deals with the topic of incomplete installations and the setting of limit stops on automatic compensating valves.
For many years now, all of the U.S. model plumbing codes have required the installation of automatic compensating type shower and tub/shower combination valves, and the setting of the limit stops. I think I’ve heard every excuse there is as to why limit stops were not set at the time of installation, and some of them have been absolutely legitimate. “The water heater was not connected when we trimmed out the showers,” and “The water service was not turned on yet,” are both are good excuses for not setting limit stops when finishing the valve; however, don’t you need to go back after the water is turned on, or when the water heater is functioning, to test the system? Most do-it-yourselfers, home remodelers, or people at the big box stores don’t have any idea what a limit stop is or how to properly set it, even if they’ve read the instructions.
I have seen too many instances where the proper valve has been installed, but the limit stop was never set correctly. The limit stops must be checked and adjusted as necessary when there is a change to the system water supply temperature; a common occurrence when a water heater is replaced.
This entire white paper can be viewed and downloaded at www.asse-plumbing.org/downloads/CompensatingValvesScaldHazards.pdf.
About 35 years ago, ASSE International developed its first product performance standard for a water temperature limiting device: ASSE 1016, Performance Requirements for Individual Thermostatic, Pressure Balancing and Combination Control Valves. This standard was followed a few years later by ASSE 1017, Temperature Actuated Mixing Valves for Hot Water Distribution Systems, ASSE 1062, Temperature Actuated, Flow Reduction (TAFR) Valves for Individual Supply Fittings, and ASSE 1066, Individual Pressure Balancing In-Line Valves for Individual Fixture Fittings. ASSE 1016 went through a number of revisions to the title, scope, and application over the ensuing years until it got to a point where the standard could no longer be revised to properly cover the many new uses/applications of water temperature control devices. A special task group was appointed by the Product Standards Committee to solve the confusion and controversy of the distinctly different types of devices that were being marketed. The result of this groups’ work was the formation of three new standards: ASSE 1069, Automatic Temperature Control Mixing Valves, ASSE 1070, Water Temperature Limiting Devices, and ASSE 1071, Temperature Actuated Mixing Valves for Plumbed Emergency Equipment. We were sure that the confusion would stop and everything would be peachy. Well, we’ve all heard about how old habits are difficult to break (and all the other excuses for not changing one’s thinking). It almost seemed like the confusion intensified.
This is why the Scald Awareness Task Group was given the task of writing a paper and creating a simple-to-use guide to clearly explain where temperature control/limiting products listed to ASSE standards should be installed.
Our fourth paper, Guidelines for Temperature Control Devices in Domestic Water Systems, was published in Sept. 2016. Each temperature control/limiting device covered by the seven ASSE product performance standards has specific applications as to where they are to be used. However, over the years, ASSE International had been receiving calls from inspectors, installers, and others asking if certain types of devices are approved to be used in certain installations. Of course, the Authority Having Jurisdiction (AHJ) has the final approval of all installations, but one must be aware of the manufacturers’ installation requirements, which may exceed the prevailing code.
In some applications, installing the wrong device or installing it in the wrong location can lead to potentially serious scalding situations. It can be the same as if no temperature control device was installed, thus exposing the end user to potentially scalding hot water temperatures. Furthermore, installing the wrong device can lead to a false sense of security. Therefore, it is extremely important to ensure that the proper device is installed in the proper location.
There are many devices in the marketplace listed to multiple standards (i.e. ASSE 1017, ASSE 1069, and/or ASSE 1070). Devices listed to multiple standards are approved for each particular application in accordance with the listing relevant to its use. While these devices listed to multiple standards are designed to be installed in more than one application, a single device should not be installed to control the entire temperature of the distribution system while simultaneously serving the needs of a fixture(s).
When a device listed to multiple standards is installed at the point of source or supply (at or about the water heater) as a temperature control device for a potable water distribution system, it is considered to be an ASSE 1017 device. It does not negate the requirement of an ASSE 1016, ASSE 1069, or ASSE 1070 type device, where required, to control the water temperature at the point of use.
Dual-listed devices should be installed in accordance with one of the listed standards. When installed in a particular location, the device should not be used to satisfy the requirements of multiple listings. Each device should be installed within the scope and application of one of its respective standards.
The paper simply lists the seven product performance standards along with the requirements of each standard. Using the table below, simply ask yourself a few easy questions:
- Will the device be used to control the temperature of the hot water distribution system?
- Do I need to provide scald or thermal shock protection, or both?
- Will further mixing happen downstream?
- Will the device be the final temperature control?
By plugging your answers into the chart, you can narrow down your selection
The entire white paper can be viewed and downloaded at www.asse-plumbing.org/downloads/ASSE_Guidelines_For_Temp_Control_Devices.pdf.
The task group is currently working on a new white paper for the recommended installation practices for residential water heaters to reduce the danger of scalds. We are just getting into the meat of the topic, but expect to finish in the next few months.
Many people have contributed much time and effort to complete these papers. Our goal is to let you and others know that scald burns do happen, but they are preventable through knowledge and good common sense.
