What is a Tempering Valve and How Does It Work?

A tempering valve is a crucial part of many plumbing systems, designed to keep your hot water at a safe temperature. If you’ve ever wondered, “What is a tempering valve?”, it’s a device that mixes hot and cold water to deliver water at a set temperature so you don’t get scalding hot water from your taps.

This is especially important for households with sensitive skin, high risk individuals or young children.

Whether you have an existing hot water storage system, tankless continuous flow or simply a brand new hot water system, having a tempering valve installed means comfort and safety throughout your home.

How Does a Tempering Valve Work?

A tempering valve controls hot and cold water flow to keep the water temperature safe and consistent. Inside the valve, a thermostatic temperature sensitive element responds to temperature changes in the hot water supply.

Laws in place across Australia require hot water connected to plumbing fixtures used primarily for personal hygiene must not exceed 50°C. However, heated water needs to be at 60°C to prevent the growth of legionella and other bacteria. Which is where the tempering valve comes in.

When hot water from your storage tank mixes with cold water, this thermostatic element expands or contracts and adjusts the blend to maintain the set temperature. It means that the water coming out of your taps is warm enough for personal hygiene use without the risk of scalding and burns.

If the water gets too hot, the valve allows more cold water in. Too cold, though, and it reduces the cold water flow. Simple and effective.

Benefits of Tempering Valves in Hot Water Systems

Tempering valves are an important part of a safe and comfortable hot water system. Here’s how they benefit you:

• Prevents scalding: By mixing hot and cold water tempering valves keep the water temperature safe, reducing the risk of burns from scalding hot water.
• Safer for sensitive users: Ideal for homes with sensitive skin or high risk individuals, such as children and the elderly, for personal hygiene use.
• Reduces risk of harmful bacteria: By maintaining the correct temperature in stored hot water, they help minimise legionella bacteria growth.
• Maintaining compliance: Tempering valves help your plumbing system meet the plumbing code requirements.

Overall, installing a tempering valve guarantees you peace of mind and safe hot water supply for your home.

How Does It Differ from a Thermostatic Mixing Valve?

While tempering valves and thermostatic mixing valves (TMV) both blend hot and cold water, they differ in precision and application. A tempering valve provides basic temperature control, maintaining a consistent water temperature suitable for hot water storage systems and general home use. It’s ideal for everyday household needs, like showers and personal hygiene purposes.

In contrast, a thermostatic mixing valve offers more precise temperature control and responds more quickly to temperature changes. This makes the thermostatic mixing valve a better choice for sensitive environments, like nursing homes, hospitals, and places with high-risk persons.

But when it comes to the crunch, both play crucial roles in keeping your hot water supply safe and comfortable.

When to Replace a Hot Water Tempering Valve

Knowing when to replace a TMV or tempering valve is important for a safe and efficient hot water system.

Common signs your tempering valve may need replacing include:

• Changes in the temperature of your hot water supply (too hot or too cold).
• Inconsistent water temperature at your taps
• The valve can’t maintain the set temperature
• Your hot water system has been recently upgraded or replaced (e.g. new hot water system or hot water system replacements)

If any of these apply to you, it’s well worth installing a new tempering valve. Regular inspections by a licensed plumber can also help identify when a tempering valve needs replacing.

Types of Tempering Valves and Colour Codes

Tempering valves come in different types for different hot water systems and are marked with different cap colours. These colours identify the valve’s purpose so you can use it correctly and safely in your plumbing system:

• Orange cap tempering valve: Common for hot water tank storage systems for temperature control.
• Green cap tempering valve: Ideal for tankless continuous flow systems for consistent hot water temperature.
• Blue cap tempering valve: Used for low-pressure systems in areas with variable water supply pressure.
• Black cap tempering valve: Best used for high-temperature applications like commercial hot water systems.

Differentiating between the various types of tempering valves will help you choose the right one for your hot water unit.

Why You Need a Licensed Plumber

Whether you’re installing, replacing or servicing a hot water tempering valve (or a thermostatic mixing valve), it’s important to use a licensed plumber.

They have the expertise to install tempering valves according to plumbing code regulations so you don’t get temperature changes, pressure variations or valve failure. Improper installation can lead to inconsistent hot water temperature, scalding hot water or water too cold for personal hygiene use. A licensed plumber can also assess your hot water storage system or tankless continuous flow model to ensure everything is safe and efficient.

By using a qualified professional for new and replacement hot water systems, you’ll be compliant, your water will be safe and your hot water supply will be reliable.

Enjoy Safe and Reliable Hot Water

A tempering valve is a small but critical part of your hot water system. The way it mixes hot and cold water guarantees your water temperature is safe and consistent. It also protects your household from scalding hot water and temperature issues.

Whether you have a hot water storage system, tankless continuous flow system or are considering a hot water system replacement, a functioning tempering valve is important for safety and comfort. Remember to consult a licensed plumber for installation and servicing to get everything running smoothly.

A properly installed tempering valve gives you peace of mind knowing your hot water supply is safe and reliable for the entire family in daily use.

Please note: Thanks for reading our blog “What Is A Tempering Valve and How Does It Work?”. This information is provided for advice purposes only. Regulations differ from state to state, so please consult your local authorities or an industry professional before proceeding with any work. See After Hours Plumbing’s Terms & Conditions here.