What is a Tempering Valve?

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When it comes to your family’s safety and comfort, installing a tempering valve for your hot water system is a crucial consideration. Not only does it ensure a consistent water temperature for your showers and baths, but it also plays a pivotal role in meeting Australian safety standards. In this article, we will delve into the significance of tempering valves, how they work, and their various types to help you make an informed decision for your hot water system unit.

Understanding the Tempering Valve:

How Does a Tempering Valve Work?

A tempering valve serves as a guardian for your family’s well-being by blending hot water with cold water, ensuring that your shower and bath outlets maintain a safe temperature. This ingenious device prevents scalding accidents, making every shower experience worry-free.

Ensuring Safety and Compliance:

Australian Standard AS3500.4.2 Clause 1.6 mandates that the delivered water temperature complies with specific standards. However, the Plumbing Code of Australia (PCA) presents a unique challenge. On one hand, it requires hot water to be stored at a minimum of 60°C to prevent the growth of Legionella bacteria, which can cause Legionnaires’ disease. On the other hand, the PCA mandates that hot water for personal hygiene should not exceed 50°C. For certain facilities, such as those catering to the young, elderly, sick, or disabled, the maximum allowable delivery temperature is reduced to 45°C for safety reasons.

How a Tempering Valve Helps:

To meet both of these conflicting requirements, a tempering valve is the solution. While the hot water tank maintains the strict 60°C temperature to deter bacterial growth, the tempering valve, equipped with a temperature-sensitive element, blends cold water with hot water as it flows through the pipes. This dynamic mechanism ensures a constant, safe outlet temperature for your kitchen and shower taps. In essence, it reduces the risk of both bacterial infection and accidental scalding, offering you peace of mind.

Exploring Tempering Valve Types:

Different hot water systems may require specific types of tempering valves for optimal performance and safety.

Here’s a quick guide:

Blue Cap Tempering Valve:

Most commonly used for electric water heaters.

Green Cap Tempering Valve:

Recommended for gas hot water systems.

Orange Cap Tempering Valve:

Ideal for solar hot water and heat pump hot water systems.

Black Cap Tempering Valve:

Recommended for large-capacity systems.

Seeking Expert Advice:

If you’re unsure which tempering valve best suits your unit, don’t hesitate to contact us at 13 10 91. Our experts are readily available to provide guidance and discuss your specific needs. We proudly serve areas in Canberra, Newcastle, Central Coast, Hunter Valley, Lake Macquarie, and Port Stephens.


In conclusion, a tempering valve is an essential component of your hot water system, ensuring both safety and compliance with Australian standards. By blending hot and cold water, it maintains a constant, safe outlet temperature, reducing the risk of bacterial infection and scalding accidents.

When it comes to choosing the right tempering valve for your unit, our experts are just a call away, ready to provide expert advice and support. Make the smart choice for your family’s safety and comfort by considering a tempering valve for your hot water system.


General Plumbing & Electrical | Hot Water Systems | Blocked Drains | Gas Fitting