
Tempering valves are devices which attach to the pipes that run to your hot water system. They are responsible for mixing hot and cold water to deliver water at a safe temperature. In Australia, a tempering device is a legal requirement on all new and replacement hot water systems. We look at why tempering devices are important and examine some of the tempering valve problems you need to know about, to ensure the safety of your household.
Why Are Tempering Devices Important?
Tempering devices reduce the water temperature at the tap and are mostly connected to bathrooms. Tempering valves operate using a sliding mechanism that your plumber adjusts to ensure water supplied (when both hot and cold water taps are on) does not exceed 50 degrees. They are an important safety mechanism to keep your family, and especially children, safe.
If you have an old hot water system, you may not have any tempering device installed on it. When you replace your old hot water system, it is mandatory to have a tempering device installed.
For safety, tempering devices are recommended for all hot water systems including older versions.
Types of Tempering Devices
Tempering Valves
There are different types of Tempering Valves including blue, green, orange and black depending on your hot water system.
- Blue tempering valves are most common tempering valves found predominantly in electric heaters (hot water systems).
- Green tempering valves are found in gas hot water systems.
- Orange tempering valves are only used in solar hot water systems.
- Black tempering valves are present in commercial grade large capacity low gravity fed systems.
Thermostatic Mixing Valves
A Thermostatic Mixing Valve (TMV) can be installed on any system. It has less temperature variance. This is the type of valve the law requires for schools, child care centres and hospitals and is also becoming more popular for businesses and homes.
How Do I Know If My Tempering Valve is Faulty?
Tempering valves don’t last forever. Their lifespan is usually around 5 years. So how do you tell if you have tempering valve problems? There are a couple of tell-tale signs your tempering valve might be faulty:
- If you are noticing your water temperature is not ranging in temperature from cold to hot.
- Or if you have hot water to your kitchen and laundry (where no tempering valves should be present) but no hot water supply to your bathroom.
Tempering valve problems are often caused by a build-up of debris – commonly dirt, leaves, copper filings or plumbers tape which enter the hot water system, or block the filter. Tempering valves can also break with time. It’s important to keep on top of the efficiency of this valve to ensure your property is safe.
Preventing Tempering Valve Problems
Your plumber can undertake a range of maintenance to ensure your tempering valve is functioning correctly and it not damaged or out-dated. Regular maintenance is important to prevent problems. Here is some essential maintenance our plumbers recommend to our clients:
- Install or inspect an existing tempering valve.
An obvious one, but a crucial point, it takes 5 minutes to check an existing tempering valve – and if you don’t have one we can’t stress enough how important it is to install one. - Flushing the pipe connected to your hot water system.
Usually conducted before connecting the hot water system to the cold water supply. Preventing debris entering the hot water system or blocking the filter. - Installing an inline filter.
A tempering valve filter helps to stop any debris entering the hot water system. If you have an existing filter, your plumber should regularly inspect it to ensure the filter is not damaged or blocked and does not needs replacing. - Upgrading to a stainless steel hot water cylinder.
Transitioning to a stainless steel cylinder hot water system from older enamel and glass lined tanks. Older tanks have a higher incidence of rusting which can result in damaging the Tempering Valve’s hot water filter. - Replacing an old tempering valve with a TMV.
If you are experiencing tempering valve problems, and your plumber decides it needs replacing, you can also consider a TMV replacement. These devices are more expensive but have a longer life span. They are generally serviced rather than replaced.
How can we help?
Plumb Perfection understands the importance of preserving the safety of your family and your own. We work to educate and inform you on any plumbing issues, maintenance and prevention methods you can take.
For more information on tempering devices or how you can install the right one on your hot water system call Plumb Perfection and speak to one of our experienced plumbers. To organise a free quote across the Gold Coast call us today on 1300 368 009 or email us.


