hot water safety valve shower 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

IC/SP scald protection valves are installed within the heated system and are purely water temperature sensing. The IC/SP scald protection valve will initiate flow when the thermostatic actuator senses water temperature above the valve’s set-point (typically 98°F [36.7°C]) and will remain open as long as the discharge water temperature is within 10˚F of the open set-point (typically above 95°F [35°C]). The thermal actuator is always wetted, making this valve preferable for heat traced lines where scald protection flow is not required unless heat tracing fails.

A safety hazard for plant personnel can occur when utilizing safety showers, facewash, or eyewash stations if overheating of the pipes caused by solar radiation or steam/electric tracing results in extremely high temperatures at the point of use. For this reason, a scald protection valve should be implemented to protect facility personnel from excessively hot temperatures being released from the fixture and causing severe damage to the skin.

The IC/SP valve prevents this safety hazard. When installed in safety showers, eyewash stations, and other locations exposed to the same source of overheating as the system, the IC/SP will be heated just as the pipe system. The valve will open to establish flow until the over-temperature water is eliminated and it will then modulate closed.

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.

Our patents on technologies serve as the backbone for many products in commercial and industrial water temperature control markets. From pressure balance to digital mixing valves we strive to bring safety and comfort to modern plumbing.

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.

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.

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.

Have you ever been taking a shower when the water from the showerhead suddenly becomes scaldingly hot or icy cold? That sudden temperature change is due to a drop in either the hot or cold side water pressure. This can happen when someone else in the house turns on the water at a fixture, when the washing machine fills, when a toilet flushes, or even when the dishwasher begins a cycle that uses water. Sometimes the situation is just startling and annoying, but a sudden blast of hot water can also create scalding burns.

A pressure-balance shower valve or thermostatic shower valve can remedy this issue, and they are now required by building codes in some areas (particularly in high-rise buildings) for new construction or during remodeling.

Pressure-Balance Shower Valve: This option operates by sensing the volume ratio of hot water to cold water and adjusting them to continually deliver water at your chosen temperature. As you turn on the water with a single handle, you are controlling both the volume and the temperature at the same time. As you twist the control, the volume of the water increases at the same time you are increasing the temperature.

Thermostatic Shower Valve: This option operates by sensing the actual temperature of the incoming water and adjusting hot and cold flow to maintain a steady temperature. With these shower valves, you generally set the water temperature and water volume with individual controls: These valves have two controls, one for temperature and one for volume. The water temperature remains the same, no matter if the water is trickling or running full blast. This type controls the temperature to within one degree of whatever setting you establish with the temperature control. The chosen temperature will remain at the same setting after you turn the water off, so the next shower will automatically be set exactly where you left it. Thermostatic shower valves are regarded as far superior to pressure-balance valves, but they are also much more expensive.

A pressure-balance shower valve works by maintaining a balanced flow of water between the hot and cold sides. They do not actually sense the temperature of the water. The valve has either a balancing spool or a diaphragm inside the valve body that reacts to drops in the pressure of one incoming water supply (either hot or cold) and adjusts the outflow of the opposite water supply to match. This ensures that the water doesn’t get suddenly colder or hotter as it emerges from the spout of the showerhead. Sudden changes in supply water pressure may reduce the outflow of water from the showerhead, but it will not change the temperature.

Thermostatic shower valves use a more sophisticated mechanism that actually senses the temperature of the water rather than merely reacting to the volume of flow between hot and cold inputs. A wax element inside the shower valve expands or contracts in reaction to heat, changing the amount of water allowed in from each inlet. While this might sound virtually the same as the less expensive pressure-balance valve, there are key advantages:

You can set the water heater at a high-temperature setting, yet the shower valve itself can be limited so that the water temperature never reaches a scalding level. This allows washing machines, dishwashers, etc., to use much hotter water than you want in a shower or bathtub.

Pressure-balance shower valves are usually one-handle designs that can fit into the same wall or surround openings where an old standard single-handle faucet fits, but the conversion to a pressure-balance valve sometimes does require some changes to the hot and cold water supply piping and the shower standpipe in the wall to allow the new valve to fit. If you aren"t comfortable enough with your plumbing skills, consider hiring a plumber.

Thermostatic shower valves come in many styles, but typically the separate volume and temperature controls are part of a single-valve body that is covered by a large escutcheon plate. This usually requires some modification to the wall or surrounding opening to fit the new, larger valve mechanism. Some types, however, use a streamlined profile in which the temperature control is mounted directly on the volume control handle. Alterations to the water supply piping are again sometimes necessary. Many people choose to have a professional plumber install this kind of valve, considering that the cost of the valve itself can easily run $200 or more, making installation mistakes costly.

Like older standard shower valves, pressure-balance shower valves have inner cartridges that wear out and eventually go bad. When it does, the cartridge may not mix the water evenly and you might get mostly hot or mostly cold water. Or, you may also get barely any water at all. These are all signs that you need to change out the cartridge. Once a new cartridge is installed in a pressure-balance shower valve, it should work like new. You can extend the life of the shower valve by turning it on regularly, even if that bathroom does not get any use. A valve that sits without use for too long is more likely to go bad than one that is used regularly.

Thermostatic shower valves also have cartridges that wear out and need replacement, but they are also susceptible to problems originating with dirt or debris in the check valves that control the flow of water from the hot and cold inlets. If your thermostatic shower valve suddenly stops controlling the water temperature or water volume correctly, the first step is to inspect and clear the check valves, following the manufacturer"s directions. If this doesn"t solve the problem, then replace the cartridge.

When installing a new pressure-balanced or thermostatic shower valve, save the paperwork because it will make it easier to identify which replacement cartridge you need when the time comes to change it. Sometimes a quick call to the manufacturer can result in a free new cartridge, so keep the phone number handy.

A little over five years ago, an article titled “When Will the Confusion End?” was published in ASSE’s former publication, Backflow Prevention & Plumbing Standards (BPPS) magazine. That April 2016 article hoped to explain which water temperature control devices should be installed for particular applications and why. Feedback, at that time, agreed that it helped, but more information was needed.

Since then, ASSE’s Scald Awareness Task Group published a white paper titled, “Guidelines for Temperature Control Devices in Domestic Hot Water Systems,” along with a corresponding “pocket guide,” which outlines the proper water temperature control device to be used in various applications. Additionally, ASSE International published three new product performance standards for water heaters that precisely control their outlet temperature. All of these tools can help you make your temperature control device selection more easily.

These devices are to be used, as the title states, for individual showers and tub/shower combinations ONLY. This type of device provides both scald and thermal shock protection installed at the point of use and is the final temperature control with no further mixing allowed. We should all know by now that three types of valves meet the 1016 standard:

Type “P” devices sense the cold and hot water supply pressures and adjust for any variations in these pressures to maintain the outlet water temperature.

Type “T/P” devices sense the cold and hot water supply pressures and outlet water temperature, and adjust both the pressure and temperature variations to maintain the outlet water temperature.

These devices are to be used to control the temperature of the hot water distribution system and to be installed at or near the hot water source. These devices are for hot water distribution systems ONLY. Since this type of device does not provide scald or thermal shock protection, additional downstream temperature control devices are required. A working group is currently looking at possible revisions to this standard.

These devices can be integral or added on to fixture fittings such as showerheads, bathtub/whirlpool tub spouts, and some sink fittings. They are designed to reduce the flow to a trickle (0.25 gpm or less) within 5 seconds in response to a temperature greater than a preset outlet temperature. These devices ONLY provide scald protection.

These devices are used to equalize incoming hot and cold water pressures in order to minimize the outlet temperature variations when used with a mixing valve or two handle valve set. They DO NOT provide scald protection but DO provide thermal shock protection.

These devices supply tempered water ONLY at a preset temperature to SINGLE pipe gang (group) showers and sitz baths. They provide BOTH scald and thermal shock protection. The end user has no control of the final temperature.

These devices limit the hot or tempered water temperature to fixture fittings such as sinks, bathtubs, bidets, and lavatories to reduce the risk of scalding. Mixing with cold water at the point of use is intended. They ONLY provide scald protection.

These devices are intended to be a component of eyewash, eye/face wash, drench showers, and combination units to provide tempered water in compliance with ANSI Z358.1. These devices ONLY provide scald protection.

Water heaters, both tank type and tankless, listed to this standard control the outlet temperature to the hot water distribution SYSTEM at a defined setpoint under various steady-state flow conditions. The limits of this setpoint are very similar to those of ASSE 1017. This type of water heater does NOT provide scald or thermal shock protection. Additional temperature control devices are needed downstream at the point of use. Essentially, this type of water heater has a similar built-in means to control the outlet water temperature to the distribution system as adding a 1017 device to a tank type or tankless water heater.

Water heaters listed to this standard precisely control the outlet temperature under varying flow conditions to provide tempered water at the point of use. Mixing with cold water at the point of use is intended. These water heaters provide a level of scald protection consistent with ASSE 1070 devices. They are NOT intended to be a substitute for an ASSE 1016 device. This type of water heater is essentially a point of use water heater that controls the outlet temperature, similar to adding a 1070 valve to the system at the point of use.

Water heaters listed to this standard control the outlet water temperature to a precise setpoint at varying flow conditions to supply tepid water to emergency equipment in compliance with the range listed in ANSI Z358.1.

These 10 product standards give us the valves, faucets, fixture fittings, devices, and water heaters that can be used to help us as designers, engineers, installers, and inspectors to prevent the potential for scald injuries and slip/fall injuries due to thermal shock. So, now that we have all of this information, what is the simple and easy way to choose the correct device? The Scald Awareness Task Group put this chart together to help with that selection, but first, you must ask yourself a number of questions:

Something else to consider — electronics have been part of our plumbing world for some time now and they are constantly making a larger impact on the industry. It all began with the advent of sensor-controlled faucets that deliver tempered water at a predetermined temperature; these require a 1070 type device to control that tempered water temperature.

Today, we have digitally controlled shower and tub/shower combination valves, and digital controls for hot water distribution systems, and plumbed emergency equipment.

One of the newer features that I really enjoy is the LED temperature indicator on my showerhead. This lets me know, at a glance, the temperature of the water at the showerhead — both by looking at the color and the actual temperature displayed. My particular showerhead shows BLUE until it reaches 90 °F, changes to GREEN at 91 °F and changes to RED at 109 °F. I have my high limit stop set at 112°F. I find this feature to be very handy. Many manufacturers of showerheads and body sprays are incorporating some form of this feature into their products.

Even after choosing the correct device and installing it correctly, our job, as the installer, is not done until we instruct the owner or the owners’ representative on how to adjust the device to ensure that it continues to work as it was intended. This is particularly true with shower or tub/shower combination valves; the limit stop must be set at the time of installation — the plumbing code says so and manufacturers’ installation instructions say so. Using the excuse, “We didn’t have hot water when I installed the shower valve trim,” doesn’t cut it anymore … you need to go back after the water heater is installed and complete the installation by setting the limit stop on the shower valve. And remember, Type “P” shower valves must be checked and possibly reset seasonally, as the incoming cold water temperature changes or when the temperature setting of the water heater is either increased or decreased.

This article describes key safety inspection points that should be examined when inspecting building hot water supply anti-scald protection and tempering valve or mixing valve or temperature compensating valve installations.

We discuss temperature or scalding safety, valve adjustment, and leak concerns at mixing valves, and we include manufacturer"s instructions & warnings about mixing valve installation, safety, and periodic inspection & maintenance.

Watch Out: are there temperature control devices installed on the building hot water supply system? In most jurisdiction scald protection is required for residential properties but it may not be specified by local codes for commercial properties.

Check the temperature control settings on the device and where appropriate, actually measure hot water output temperature at the fixtures closest to hot water supply in order to assure that the mixing valve has been set to protect the building occupants from scalding.

Remember that while these valves may show a target temperature on the valve setting knob, the actual water temperature that comes out of a building faucet or tap will vary and may be hotter or cooler than the actual temperature set.

This is not precise lab-grade equipment capable of controlling water temperature precisely, and more, the length of pipe run between the hot water source and the building faucet or fixture will affect the temperature of water received there. A long run of un-insulated hot water pipe will deliver cooler water than a well-insulated water supply pipe of any length.

See TANKLESS COIL / HOT WATER COIL LEAKS for a detailed discussion of how to recognize, evaluate, and repair leaks at tankless coils on heating boilers

At above left we illustrate the typical piping arrangement into and out of a tankless coil water heating system. Cold water is piped to an inlet marked "COLD" and building hot water supply piping is connected to the tankless coil outlet marked "HOT".

This tankless coil piping example from Crown Boilers indicates the use of a mixing valve or anti-scald valve right at the heating boiler. The company includes an interesting warning reading as follows [Quoting - Crown BDS Installation Manual]

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.

Using the modern Watts Regulator Co. Series LF1170 / LFL1170 Hot Water Temperature Control Valve instructions as an example, these valves control water temperature in the following ranges:

Watts Series LF1170 and LFL1170 Hot Water Temperature Control Valves INSTALLATION INSTRUCTIONS[PDF] Installation, operating, and adjustment instructions for the LF1170 and LFL1170 mixing valves.

Watts Series LF1170 and LFL1170 Hot Water Temperature Control Valves SPECIFICATIONS[PDF] (2019), Watts Regulator Co. (2013), USA Tel: (978) 688-1811, Fax: (978) 794-1848,

Excerpt: This 1 inch lead free hot water control valve is designed for installation on water heating equipment to provide tempered water to point-of-use fixtures and is ideal for radiant heat applications.

It consists of a lead free brass body, solder union connections, solid wax hydraulic principle thermostat, integral filter washers and check valves, virtual shutoff upon loss of cold water supply, and a locking mechanism for the temperature setting.

Carson Dunlop Associates, THE IMPORTANCE OF THERMOSTATIC MIXING VALVES TO PROTECT AGAINST SCALDING: Part ONE [PDF] Carson Dunlop Associates, School of Home Inspection, retrieved 2022/08/14, original source: https://www.carsondunlop.com/training/resources/the-importance-of-thermostatic-mixing-valves-to-protect-against-scalding-part-one/

Excerpt: Anyone that has been scalded knows how painful it can be. When water is hot, it doesn’t take long for flesh to burn, and children’s skin burns more quickly. Also, at higher risk areolder people who react more slowly, and are more susceptible to burns as a result.[See details at TABLE OF SCALDING TEMPERATURES & TIMES]

Carson Dunlop Associates, THE IMPORTANCE OF THERMOSTATIC MIXING VALVES TO PROTECT AGAINST SCALDING: Part TWO [PDF] Carson Dunlop Associates, School of Home Inspection, retrieved 2022/08/14, original source: https://www.carsondunlop.com/training/resources/the-importance-of-thermostatic-mixing-valves-to-protect-against-scalding-part-two/

Due to the safety importance of this issue, ensure that the home inspector training program you select includes training on thermostatic mixing valves, so that you can provide the necessary advice for your clients.

Illustration: The Watts LF1170 or LFL1170 temperature control valve. Temperature an be adjusted by loosening a hex screw in the valve cap and rotating the cap - as described above.

At the plumbing fixture outlet hot water temperature must be at or below the highest temperature allowed by local building codes. These temperature specifications vary by U.S. state and in Canada.

See TABLE OF SCALDING TEMPERATURES & TIMES - where we explain how long it takes for hot water to cause a burn and where we cite regulations about water temperature control and anti-scalding requirements.

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.

A point of supply pressure balancing valve or automatic mixing valve (or a manual mixing valve) can be installed at or near the water heater, or at the tankless coil or other hot water source so that scald protection is provided even if the water heater is set to a high temperature.

An temperature-sensing thermostatic mixing valve or anti-scald device can be installed at or near the water heating device so that even if the water heater is set to a high temperature (to obtain more total hot water as we discuss

MIX VALVE SCALD PROTECTION, Best Practices, includes excerpts or adaptations from Chapter 6 of Best Practices Guide to Residential Construction (found at page bottom, Click to Show or Hide), adapted courtesy of Wiley & Sons and written by Steven Bliss.

The other type of thermostatic valve is built into some high-end showers (Figure 6-54) courtesy of Steven Bliss, Best Construction Practices author. These devices allow the user to set the temperature on a dial when showering.

The unit will compensate for changes in either pressure or temperature to maintain a constant delivery temperature and flow rate. If the cold water fails or the tempered water is still too hot for any reason, the unit will shut off the flow.

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 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]

Hi, my hot water tank uses a Watts LF1170 Series Mixing Valve, I simply cannot find any videos online how to adjust that red nob to increase the temperature, it has a mini hex wrench that I have to losen the cap but I have never done this before and I don"t want to cause any leak. I would help to have a video or something showing the exact steps, thanks

No the anti-scald valve simply mixes cold in with outgoing hot to avoid scalding temperatures. But any valve can become clogged with scale or debris, as can other pipes and heating equipment.

We"re flying a bit blindly here Steve but it does not sound right for warm water to immediately re-heat the cold-in piping on the cold side of the tempering valve immediately after turning off the flowing hot-water.

If the back- flow were substantial I"d expect cold piping on the cold side of the water heater to get hot so far back into the system that warm water would come out of nearby cold faucets.

Just checked - the cold water inlet pipe is warm to touch down to and including where the cold water enters the system, also where the cold water enters the hot water cylinder. Yes the pipe cools immediately the hot water is turned on. It also appears to get warm immediately after turning of the hot water.

Keep in mind we"re only discussing water temperature, not hot water quantity - so when you say "more hot water" - more or less *quantity* of hot water is only affected indirectly by a mixing valve, in this manner:

Also keep in mind that depending on the brand and model of mixing valve, the outgoing water temperature may be affected by the incoming water temperature on both the cold and hot side. If you are out of range of the incoming hot and cold temperatures - such as those shown in the table in the article above - the outgoing water temperature may be out of spec too.

I have been told that my Mixing Valve needs to be replaced, I have a gas water heater and solar panels also for hot water, it was installed in 2009. How can I be sure this is necessary. Five years is very little time and the expense is very large.

Continue reading at ANTI SCALD VALVE PROTECTION, Best Practices or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

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

"BDS Series Oil-Fired Hot Water Boilers, Installation Instructions, Models GS-080 -> Crown BDS-236", Crown Boiler Company, BDS 12-99, Crown Boiler Co.

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

Few things are more frustrating than looking forward to awarm, relaxing showerafter a long day, and instead having to endure an oscillating stream of scalding and glacial water because something to do with the temperature is all messed up. But before you go tearing yourshower headout of the wall and calling up a plumber, there are a few things you can do to hopefully get your water temperature back to normal. Here they are, per Paul Abrams, ofRoto-Rooter, andBailey Carson, of Handy, an online marketplace for cleaning, installation and other home services.

Wait a WhileThe most obvious cause of fluctuating water temperatures, according to Abrams, is simply “running low on hot water from the water heater.” He says, “This happens if you’re last in line for a shower at your house, or if you have an undersized water heater. One thing I learned at my in-laws’ house is that my father-in-law likes to stick it to The Man and remove the water flow restrictor in the shower head, which means water is pushing through much faster than it’s supposed to, and it quickly depletes the supply of hot water in the tank. When hot water starts running out, we users tend to turn the handle to a hotter setting in desperation, and we get very hot or very cold water and decreased bandwidth in the warm range.” So, if someone showered before you, wait a little while so the water heater can fill back up.

Adjust Your Mixing Valve/Scald Guard“In most instances, your scald guard — a plastic disk with notches — simply needs to be adjusted,” says Carson. “To adjust the water valves and scald guard, the single handle can be easily removed by loosening the screws with a wrench and lifting from the faucet. You’ll want to adjust the dial of the temperature controls accordingly to balance out the hot and cold water valves.” You can see exactly how this is done, with two different kinds of knobs, in the videos below.

Abrams warns, however, that you should take it slow when adjusting your scald guard, or else you could end up making the water temperature dangerously hot. “It’s important to note that faucets are set at the factory to a safe setting to prevent scalding, which is especially important to remember if you have babies, children and elderly people in the house,” he says. “This adjustment is the last safety device to prevent you from scalding yourself, and it was no doubt put in place after some expensive lawsuits were filed against faucet manufacturers. If you adjust this device, do so in one or two tiny increments at a time, then test the water temperature with your hand. Being a tough guy and pushing the setting all the way to the hot setting is a recipe for disaster, especially if your water heater is already set too hot — water heaters should be set to 120 degrees Fahrenheit, but many people crank them up much higher.”

Replace the Faucet Cartridge AltogetherIf, when you go to tweak the scald guard, you notice that the whole thing is looking worn down, you should probably go ahead and replace the whole cartridge. “With usage and time, these cartridges will fail,” Abrams says. “If your shower has no warm range, but goes from very hot to very cold, it’s probably time to replace that faucet cartridge. Many manufacturers guarantee their cartridges for life, and they’ll ship you a new cartridge for free. However, switching out the cartridge isn’t something every person is willing to try. Often, it’s a simple job, but if the cartridge is crusted over with hard water deposits, or it’s been in there for years, getting it out with a pliers can prove to be very difficult.”

So, if changing the cartridge yourself is too much trouble, as Carson says, “Let a professional handyman handle it for you.” Which will be especially necessary if you did end up tearing your shower head out of the wall, after all.