Hot Water Tempering Valve - replacement, cost & requirements

Frequently asked questions about hot water tempering valves

We compiled a list of the most common questions about tempering valves and tempering valve replacement our plumbers get asked. Find the answers below.

What is a Tempering Valve?

A hot water tempering valve is anti-scald device and it’s designed to mix cold and hot water.

To keep us safe from hazards such as Legionella, our storage hot water system maintains a temperature of between 60-70 degrees. The tempering valve then mix it hot water with cold water to deliver it at around 50°C. 

Installing a hot water tempering valve is an important safety measure. It ensures that the stored water in your tanks remain safe to use without risking possible burn injuries while also preventing harmful bacteria

tempering valve replacement

Is a Tempering Valve required in NSW?

In the state of New South Wales, Australia, it is mandatory for all homes and businesses to have a temperature control device installed in their hot water system. A tempering valve is a vital safety component in any domestic hot water system. Without a tempering valve, there is a risk that the water could be too hot, posing a scalding hazard. In addition, a tempering valve helps to regulate water pressure, ensuring that the flow of water is not too high or too low.

Installing a tempering valve may seem like an unnecessary expense, it is an important safety measure that can help prevent serious injuries.

What happens when Tempering Valve fails?

When a hot water tempering valve fails, the water heater will no longer be able to heat the water to the desired temperature. This can lead to many problems, including scalding, water line freeze-ups, and sediment buildup in the tank. Scalding is a serious safety concern, as it can cause severe burns. Water line freeze-ups can also be a problem, as they can cause the pipes to burst. In addition, sediment buildup can lead to the need for more frequent maintenance of the water heater. 

How much does it cost to replace a Tempering Valve?

The cost of replacing a hot water tempering valve can vary depending on the type of valve, the unit’s size, and the installation’s complexity. In general, however, a tempering valve will cost anywhere between $150 and $200. The labor costs associated with the tempering valve replacement will depend on the plumber’s hourly rate and the time required to complete the job. It is typically possible to complete the work in one to two hours for a standard installation. The total cost of replacing a tempering valve can range from $250 to $600.

How often should a Tempering Valve be replaced?

How often you need a tempering valve replacement depends on several factors:

  1. The quality of the valve itself will affect how often it needs to be replaced.
  2. The water conditions in the area where the valve is installed can also impact replacement frequency.
  3. The amount of use will also play a role.

How often should a tempering valve be replaced?

The valve should last you a long time, between 5-10 years, so you may not need to replace it before you replace the heater itself. You might get the life of the heater out of it.

What are the most common signs your Tempering Valve is failing?

The most common sign that your tempering valve is failing is when your hot water suddenly turns cold or vice versa. If you notice that the water temperature in your shower or sink fluctuates for no apparent reason, your tempering valve likely is to blame.

Another common symptom of a failing tempering valve is when the water pressure in your home becomes inconsistent. One minute you may have substantial water pressure, and the next, it may be practically non-existent. This can be extremely frustrating, and it’s often a sign that you need a tempering valve replacement.

What types of valves are on the water heater?

There are three types of valves:

  • Tempering mixing valve
  • Pressure limiting valve
  • Thermostatic mixing valve

What is the difference between a Thermostatic Mixing Valve (TMV) and a Tempering Valve?

Thermostatic Mixing Valves (TMVs) have a fail-safe. That means it will shut the hot water off if it’s not mixing with cold water. TMV is mandatory for commercial buildings, nursing homes, daycare centers, and commercial buildings where there are elderly, young kids, or disabled people. 

However, TMVs are not mandatory for domestic houses. Instead, there is a tempering valve to control the temperature, but if that fails, you might get scalding hot or freezing cold water. 

Where is the Tempering Valve located?

A tempering valve is located externally on the hot water system. It is installed between the cold line and the hot water line. Depending on what type of water heater you have the Tempering Valve can be either orange (used in solar heaters), blue (most likely if you have an electric hot water system), green (gas heaters) or yellow (if you have instantaneous heater)

Are all Tempering Valves the same?

There are a few different types of tempering valves on the market, but they all serve the same purpose. While there are a few different designs, all tempering valves use a similar operating principle. A diaphragm or plunger controls the flow of water, and a spring helps keep the valve closed when there is no water flow. As water flows through the valve, the diaphragm is pushed open, allowing hot and cold water to mix. The amount of mixing can be adjusted by adjusting the spring tension. 

If you have any other questions regarding tempering valve replacement or tempering valve installation, get in touch with Ironclad Plumbing Blue Mountains. We can help you with hot water repair, installation and maintenance. Give us a call on 02 4760 0441 or fill out the online enquiry form.

For all Blue Mountains residents, check out our hot water system installation and repair page.

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