What is a tempering valve?
Tempering valves are valves that act like a thermostat. They blend hot and cold water, allowing you to maintain constant and safe water temperatures in your home. By mixing the water within your pipes, it allows you to keep your hot water tank above 60oC and still not exceed 50oC out your tap. This reduces the risk of any bacterial build-up in your water tank, while ensuring you don’t get scalded either.
Tempering valves come in four varieties:
- Blue Cap – ideal for electric storage and some heat pumps.
- Black Cap – usually used in large capacity water systems.
- Orange Cap – good for solar and heat pump hot water systems.
- Green Cap – recommended for gas heated water systems.
Do I really need one?
Yes, you do need to install tempering valves. You need tempering valves due to specific Australian laws on hot water systems.
The Australian Plumbing Code is very specific with regulations and standards about water temperatures in in AS/NZS 3500.4:2018, stating that:
- New hot water installations and systems shall supply heated water not exceeding 50°C.
- To avoid the manifestation of the bacteria growth legionella, a heated water installation shall store water at a temperature at a minimum of 60°C.
Why do I need to install one?
By law, your hot water tanks must maintain at a minimum temperature of 60oC. However, the water coming out of your tap in washrooms / showers must not exceed 50oC. So, in order to comply with hot water systems Queensland laws, you need to have tempering valves installed.
The reason for the minimum water tank temperature is to prevent the build-up of Legionella bacteria, the bacteria responsible for Legionnaires’ disease. However, the water coming out of your washroom basin and showers must not reach temperatures greater than 50oC to avoid you and your family being scalded.
You must have your tempering valves installed by a licenced plumber. The installation must also be undertaken according to the Plumbing Code of Australia. This means you need to have them installed on any new hot water system or as in most new builds just on the hot water supply to the bathrooms.
How does it work exactly?
Tempering valves are temperature sensitive valves. This means they will vary the amount of mixing of hot and cold water that occurs depending on the temperature. Your hot water tank will be set to the required minimum of 60oC, with the tempering valve set to a maximum of 50oC.
Once the water temperature passing the valve reaches this maximum, it allows more cold water to pass through. This in turn reduces the temperature of the water to keep it under this maximum and it also reduces the demand on your hot water tank as well.
How long does it last?
As with any plumbing fixture, your tempering valves will begin to deteriorate over time. However, the expected lifespan of a tempering valve within a well-maintained plumbing system is about 5-8 years. Regular flushing, audits and maintenance of your plumbing systems by a plumber, along with the installation of filters, can help to prolong your tempering valve’s lifespan.
Still confused about tempering valves?
The team at Sunpak Hot Water are constantly updated with the best practices and all of the relevant Australian standards. If you’re in need of any advice regarding tempering valves or if you have any queries about your hot water systems, the team at Sunpak would be happy to help you out.
Give us a call on 0405 846 465 or request a quote from us today. Since you are already here, check out our latest projects and our Facebook Page!
