During much of the year on the Gold Coast we frequently hear clients ask why do I need to maintain my hot water system there is nothing wrong with it and I’m still getting plenty of hot water. In summer it is easy to forget just how much we depend on our hot water systems for showering, bathing, cooking, washing dishes and washing laundry.
But by April many people suddenly appreciate just how important their hot water system is when it fails to deliver enough or frequently no hot water. Frequently the signs that there is a problem with the hot water system have been there for months and often would have been diagnosed and rectified as part of an annual service. Because hot water systems appear to be complicated many people adopt a head in the sand approach but in reality like most working fixtures in your home they will always benefit immensely from a bit of routine maintenance
In over 37 years of experience we at Whywait Plumbing are well aware that Murphy’s Law applies usually in a spectacular fashion to the failure of a hot water system with most of them failing and leaking late at night usually when it is very cold. In all honesty basic maintenance of your hot water system is fairly simple but vitally it can double the effective lifespan of your hot water system.
To maintain your hot water system the main things you need to allow for are:
- replacing the sacrificial anode every 5 – 7 years
- flushing out all of the minerals and sediment that over time are deposited in the bottom of the storage tank every 3 – 5 years
- have the tempering valve maintained, tested and certified every year
- flush the temperature and pressure relief valve (TPR valve) every 3 – 6 months
- replace the temperature and pressure relief valve (TPR valve) every 3 – 4 years
- replace the expansion control valve (ECV valve) every 3 – 5 years
Apart from flushing the temperature and pressure relief valve (TPR valve) all the other work is legally required to be undertaken by a licensed plumber.
Most concerning from our perspective is the failure to replace the sacrificial anode which is the biggest single cause of premature hot water service failure. Regularly replacing your sacrificial anode will extend the life of your hot water service by ten years or even more. Whywait strongly recommend that you call us to service your hot water system and replace the sacrificial anode every 5 years as the cost of the service is minor compared to the thousands of dollars replacement costs not mentioning the inconvenience.
The one task we recommend you personally undertake is to activate and flush the temperature and pressure relief (TPR) valve. TPR valves continuously work automatically discharging hot water if the temperature or pressure of the water in the storage tank gets too high. Many people fail to understand if your TPR valve is not functioning properly it can potentially cause the tank to explode.
Flushing a TPR valve is relatively easy and straightforward, plus is something you can do yourself, but if the valve is already continually dripping water in all likelihood it needs replacing. To trigger the relief valve and flush it out all you need to do is lift the lever on the front of the valve all the way open and let water discharge from the drain pipe for 5 – 10 seconds then slowly put back the lever in place.
Very simply maintaining your hot water system is an investment not a cost.
By Gary Mays
Judging by the number of phone calls in the last few days to Whywait Plumbing there is genuine concern amongst our clients over the threats posed to them from Legionella risk in their domestic hot water systems.
We can assure you whilst there is always some Legionella risk, there is almost no risk of you or your family contracting Legionella bacteria as a result of it breeding in your home hot water system.
The outbreak of Legionella bacteria in the hot water system at Wesley Hospital that killed a 60-year-old cancer patient and left a 46-year-old woman seriously ill has minor ramifications to be sure because all hot water systems can pose a risk.
That potential risk is why Whywait Plumbing is constantly advocating appropriate maintenance on your home hot water system to minimise that risk even further.
However, there is a huge difference between your home or domestic hot water system and the warm water recirculating system at Wesley Hospital. The Legionella outbreak in their warm water system has not been as a result of contamination in the hot water storage system or the hot water pipes but appears to be literally at the point of delivery from the shower where the water is cooler.
A warm water system is vastly different to your home hot water system with Wesley’s water temperature set between 42.5°C and 43°C. This is lower than the maximum 45°C legislated in the Plumbing and Drainage Act for hospitals. This low-temperature setting is a result of guidelines from Queensland Health that dictate hot water temperatures in hospitals be reduced to avoid the possibility of serious burns to young children and elderly patients. The downside of this requirement is that the possibility of Legionella bacteria surviving in reticulation pipes is increased. Water temperatures of around 46°C will kill legionella bacteria.
Warm water systems are typically found in care facilities, such as nursing homes, hospitals and child care centres, where water for purposes such as bathing and cleaning is provided at approximately 45°C to prevent scalding.
Your home hot water system if it is a storage tank is heating the hot water to between 60°C and 70°C. If you have a tempering valve or thermostatic mixing valve (TMV) installed then that has been set to deliver hot water at 50°C at each individual tap.
If you have no tempering valve installed, you virtually have eliminated all risk. But you have increased the risk of someone suffering a scalding from hot water. As always it is about managing risk.
However, there is an urban myth prevalent that you can reduce electricity costs by turning the thermostat down on an electric storage unit to 50°C. This is not recommended for many reasons but it will not save you electricity and to physically get a thermostat down that low requires physically breaking the locking mechanism on it that allows the setting to be between 60°C – 70°C. If you want to lower the delivery temperature the only acceptable and compliant method is to install a tempering valve.
In 99.99% of cases, the temperature ranges your hot water system operates in is almost certainly killing any Legionella bacteria. The risk if any, is after the storage tank in the reticulation pipes. By turning your shower on and running the tap with hot water first then cooling down with cold water to your desired shower temperature you are virtually eliminating what risk there is.
What the outbreak at Wesley Hospital has confirmed is that there is a risk from warm water and that maintenance of your hot water systems will manage and eliminate that risk.
What Whywait Plumbing do recommend is that you take advantage of our ongoing reminders and offers to service your tempering valves. This not only ensures that water is being delivered at 50°C but eliminates any possibility of Legionella. It also ensures you are complying with the requirements of most insurance policies in ensuring that routine maintenance is undertaken plus we provide you with a written report and a form 4 compliance certificate that is further evidence of your hot water unit being compliant.