How do you adjust a faucet mixing valve?

The shower temperature control valve manages the upper limit of the heat of your shower or bath, along with the temperature settings on your hot water heater. There are two different kinds of control valves you can install to automatically control the hot water flow to your tub and shower, according to the writers at It's important to know how to properly control this temperature, as it is a safety issue.

Why Have Temperature Limiters?

Pressure balance valves control the ratio of hot to cold water as it mixes, preventing an imbalance from water usage elsewhere in the house. However, this does not actually limit the water’s overall temperature.

Pressure balance valves regulate the ratio of hot to cold water so that if someone flushes a toilet or starts the laundry, the cold water drawn away from the shower won’t result in your warm shower suddenly being composed of purely hot water. Note that this valve doesn’t consider the storage temperature setting of your hot water heater.

Legionella bacteria (the cause of Legionnaires Disease) are among many that enjoy the dark warm environment inside a hot water heater. Bacteria are one of the primary reasons you don’t want to use hot water from the faucet for medical applications like a neti pot. While this bacteria can survive in temperatures up to 120 degrees Fahrenheit, 140 degrees is inhospitable to most bacteria.

Adjusting Temperature on Shower Valves

If you are adjusting temperature on shower valves, you'll first need to understand what temperature to aim for. The experts at American Home Shield warn that the problem with keeping all water heaters at 140 degrees Fahrenheit or higher is that exposure to water that hot causes severe burns within 5 seconds.

The writers at PHCP Pros explain the history behind built-in temperature limiters, stating that the main point was to keep water heaters at a hot enough storage temperature. This temperature prevented the breeding of bacteria and allowed people to shower without the fear of burning themselves.

Most limiter valves come with a factory preset that stops your shower handle once it moves from the off-position to the “full hot”-position. This is designed as a safety mechanism. A shower handle with the limiter set to its zero position (water heater temperature) will rotate further. In homes where bathrooms are a significant distance from the hot water heaters, a lower setting on the limiter can help prevent tepid showers.

Removing and Replacing Shower Valves

To adjust the upper limit of mixed hot and cold water, you’ll need to access the valve underneath the shower handle in single-handle/mixer style showers. Most shower handles are connected with a set screw, usually a miniature flat-headed screw or a hex-head. On the Moen temperature control shower handle, that screw is underneath the handle part itself, so loosening it can be awkward. Once you’ve removed the screw, you should be able to pull the handle directly away from the wall and off of the assembly.

After removing the handle, you should see a Phillips-head screw in the center of the assembly. Unscrewing this lets you remove the plastic mount piece, revealing the restrictor valve. Pulling this directly out from the wall will remove the set of 2 white plastic rings. If you separate the two rings, you can re-combine the two so that the smaller ring’s indicator aligns with the larger ring’s “zero” setting. In this position, you have removed the restriction.

If you open the handle fully, the water will come out as hot as possible, given your hot water heater settings. By extension, if you want to lower the hot water ratio, re-combine the two rings such that the smaller ring’s indicator is further to the right from the larger ring’s zero setting. Put the reassembled rings back onto the handle assembly, followed by the plastic mount and the Phillips-head screw. Replace the handle and secure it in place with the smaller set screw. Test the water temperature and see if it’s too hot or cold, re-adjusting as needed.

Things You Will Need

  • Phillips-head screwdriver

  • Small hex key or a flat-head screwdriver

Home / How To Adjust a Tempering Valve: Tips & Insights

How To Adjust a Tempering Valve: Tips & Insights

  • Alan Tayyar
  • July 25, 2022

The hot water system in your house is of utmost importance — not only does it prevent scalding water from coming through a faucet and make it possible to use sinks, but it can help prevent the prevalence of Legionella bacteria within the hot water tank. The importance of a tempering valve cannot be understated. This temperature control method is the best way that homeowners can ensure everyone in their home is safe and healthy. 

Let’s see the importance of a tempering valve, how to fix a broken valve, and when you should call a professional to do the job for you! Contact Bayside Plumbing today to take care of your hot water plumbing needs, bathroom renovations, or other needed fixes!

What Is a Tempering Valve?

A tempering valve is a 2-inlet or 3-inlet valve that gathers water from the hot water system and integrates it with cold water. The hot and cold water mixture then travels through the faucet to the user at the sink. Most households have hot water below 60 degrees Fahrenheit, but this limit depends on the appliances, settings, and homeowners. For example, a washing machine can use hot water over 60 degrees to wash clothes. 

A tempering valve typically lasts between 5-8 years, depending on the quality of the hot water system and materials. Since materials can break down and deteriorate over time, you should have your hot water system inspected regularly to see the performance of your pipes and valves.

How do you adjust a faucet mixing valve?

How Does the Tempering Valve Operate?

A tempering valve operates differently from a thermostatic mixing valve. A tempering valve is adjustable and activated by the hot temperatures, meaning that they control the flow of hot water to prevent scalding water being delivered through the faucet to the user – this can help the safety and health of a person using a faucet in a household. 

The hot water used in the tempering valve is stored in a hot water system. The storage temperature of hot water is typically around 60 degrees, whereas the temperature of the water flowing out of the faucet is generally only up to 50 degrees Fahrenheit. 

The purpose of the tempering valve is to combine the hot and cold water to ensure the water is within 3-5 degrees of the intended temperature.

(See our latest blog relating to What Size Hot Water System You May Need for your home)

Types of Tempering Valves

Homeowners should know different types of tempering valves before trying any DIY fixes on their own.

Green Tempering Valves

Green tempering valves do not need an extra valve and have a 50-degree pre-set feature. This tempering valve is ideal for those who have gas hot water systems.

Black Tempering Valves

Black valves are ideal for large systems but have a shorter duration than other options.

Orange Tempering Valves

Orange valves are well-suited for solar water systems or pumps. This type of valve is also used for heat pump hot water systems.

Blue Tempering Valves

Blue tempering valves are the most common type of valve that helps regulate systems between 65 and 75 degrees. This type of tempering valve is the “standard” for electric heaters. 

If you are unsure what type of valve to use for your home, consider contacting a professional plumbing service to help you decide which is best for your unique needs. Since most valves are available at hardware stores and appliance stores around the country, you can easily get what you need for installation.

(Call us if you require tempering valve installation or other installation and repair services relating to bathroom plumbing or construction plumbing repairs!) 

How do you adjust a faucet mixing valve?

What To Do

Homeowners should follow a few tips when they are fixing their tempering valve or learning how to adjust tempering valves in their home:

  • Detach the protective cap
  • Gain access to the tempering valve adjustment knob
  • Check the tank’s temperature (it should be 60 degrees)
  • The taps must be close to the hot water source
  • The flow rate of the hot water in the hot water system should be at least 4 litres per minute (consider a hot water system replacement if the flow is too low) 
  • The knob of the tempering valve should be turned to the 50-degree mark 

How do you adjust a faucet mixing valve?

What Not To Do

Once a tempering valve is installed in your home, users will see how this appliance operates. The purpose of this valve is to control the hot water system, mix hot water with cold water, and prevent the hot water temperature from being too high. The hot water tempering valve controls the heat pump, ensuring the temperature is within the Australian standard maximum of 50 degrees Fahrenheit. 

If you find the water supply is not coming out of the faucet correctly or the thermostatic mixing valves are damaged, this can lead to personal hygiene concerns scalding water. In this instance, homeowners must fix their cap tempering valve before there are any warning signs.

Tempering Valves vs. Thermostatic Mixing Valve

Homeowners should know the differences between these two common types of valves when doing fixes in their homes. There are a few key aspects that set the tempering valve apart from other appliances in the home:

  • A tempering valve is accurately pre-set to 3-5 degrees, whereas the thermostatic valve is set to around 1 degree
  • The tempering valve is less expensive than the thermostatic option
  • Tempering valves have less longevity than a TMV (thermostatic mixing valve)
  • Tempering valves require less service and repairs than a TMV 
  • Tempering valves are replaced when there are signs of deterioration, whereas TMVs are typically repaired before being replaced

Signs of a Faulty Tempering Valve

There are some signs that homeowners should keep an eye out for when it comes to fixing and using a tempering valve. For example, a broken mixing valve can lead to extremely hot water or legionella bacteria — a serious issue that must be addressed due to personal hygiene purposes. 

There are times when a professional may be needed to ensure the water does not burn any user and cause further damage to the plumbing system. In this case, relying on a professional to help find and maintain a tempering valve can be the best way to cause further damage or harm yourself. This is especially true if you find that your hot water system does not adhere to the plumbing code of Australia.

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How do you adjust a faucet mixing valve?

Which way do you turn a mixing valve?

To increase the temperature turn anti-clockwise To decrease the temperature turn clockwise To set the valve to a maximum recommended mixed water temperature, see table below. Note: After adjustment replace the cap to prevent tampering. This valve must not be used to mix water above a temperature of 46°C.

How do you adjust the hot & cold water in a shower with a Moen mixing valve?

The water temperature from my Moen shower system is too hot. To adjust the Temperature Limit Stop, with the handle removed, loosen the adjustment hex screw with a 7/64" hex wrench and slide the screw downward. Tighten the hex screw. Test the hot water temperature (not to exceed 120°F).

How do you adjust a hot water temperature control valve?

Turn on the sink faucet. If it's a hot water faucet, adjust the temperature control valve located inside the faucet. The valve is usually in the middle of the handle and has an arrow pointing toward “hot” or “warm” on its face. Turn it clockwise to increase hot water temperature or counterclockwise to decrease it.