Why do I not have hot water?
May, June and July are the coldest months on the Gold Coast, and no-one wants to start the day with a cold shower in winter. Unluckily for some clients of Whywait Plumbing who are not Service Partners it is in these months they go to the shower and question why do I not have hot water?
Unfortunately, hot water systems are a case of out of sight out of mind. Continually where hot water systems are concerned, there were warning signs that there was a problem. Over the summer months, hot water problems are overlooked as the demand for higher temperature; hot water is not a critical consideration.
Several warning bulletins in Queensland have been issued by the QBCC and Queensland Health advising homeowners that their hot water systems need to be maintained and serviced frequently.
AS/NZS 3500.4:2018 Heated Water Services
The Australian standard that all hot water installation is based around is AS/NZS 3500.4:2018 Heated water services that are an integral part of the National Construction Code of Australia issued by the Australian Building Codes Board and it is all legal requirements in Queensland.
In AS/NZS 3500.4:2018 there is Appendix M which provides guidelines for the operation and maintenance of your hot water system which is below:
This Appendix provides guidelines for the operation and maintenance of a heated water system.
In order to ensure maximum performance and length of operation, water heaters should be inspected periodically.
M3 MAINTENANCE OF HEATED WATER SERVICES
Heated water services should be maintained in accordance with the following:
(a) Water treatment units: Where installed, water treatment units should be inspected periodically to ensure proper operation.
(b) Water vessels and tanks: All vessels and tanks should be inspected and cleaned periodically, and in accordance with any requirements of the regulatory authority.
NOTE: The frequency of periodic cleaning depends upon the quality of the supply water, design, materials of construction and the pipe system. Combinations of materials giving rise to corrosion should be avoided.
(c) Valves: The following valves should be inspected periodically to ensure proper operation:
(i) Temperature/pressure-relief valves.
(ii) Expansion control valves.
(iii) Thermostatic mixing valves.
(iv) Tempering valves.
(v) Other associated valves/devices.
(d) The requirements of AS/NZS 3666.2, where applicable.
Common reasons for why do I not have hot water
Below are listed the most common reasons we attend to clients jobs who call up to as why do I not have hot water? Listed are elementary troubleshooting ideas that you can undertake yourself to resolve or understand why your hot water is cold:
- blown fuse or circuit breaker – replace the fuse or reset the circuit breaker and if it blows again it’s probable there is a fault with your element or thermostat, and you need to call Whywait out to repair
- Energex relay switch failure – this is not the easiest to detect but if you are on off-peak rates and there are no obvious electrical faults or water leaks then its worth a phone call to your energy supplier to check whether the relay switch has failed to activate in your area
- defective relief valve – most relief valves on the side of the HWS only have a life span of around 3-5 years. Still, they can jam open so first check if you see water running from it by pulling the lever up and then easing back down again. If water continues to run then you need to call Whywait out to service the unit
- no water at all – this is when you wake up turn the tap on and cold water flows, but there is no flow from the hot water. Frequently this a failure of the non-return or isolating valve and a quick way to check is to turn the handle on the valve all the way off and then all the way back on. In many cases, the hot water will simply begin to flow again. However, if there is still no flow you need to call Whywait out for repairs
- water fluctuation from hot to cold – there are several reasons for this occurring, but the most common is a faulty tempering valve. There is nothing you can do to solve fluctuation other than call Whywait and read our information on tempering valves
- water leaking from hot water tank – there is only a maximum of 7 possible points on an HWS tank where there are joints that can possibly leak. Only 2 of those are concealed in the housing so if the water is leaking from the tank and its not from the visible water connections you need to call Whywait for service to check the HWS. In all likelihood, if the hot water tank is more than ten years old then its a 50/50 chance you need a new one installed
The above reasons are the most common problems you will experience with why do I not have hot water. As you can see above, there are only a few simple DIY solutions when you have no hot water.
A word of warning though. Please never open up the housing near the bottom of the tank where the electrical connections are as they are all live wires inside there and therefore very, very dangerous.
Whether you have a solar, heat pump, gas or electric hot water system they do need periodic maintenance so for all hot water problems call Whywait Plumbing now on (07) 5580 4311 as we guarantee a same-day rapid response for hot water problems.
Every week we have clients asking why we are required to install a TMV or tempering valve to their hot water system. The short, simple answer is because it’s the law.
The longer answer is because it’s about safety. A TMV or tempering valve reduces the risk of scalding. This is because storage type gas, electric, solar and heat pump systems are storing hot water at between 60° C and 75° C. You need to be aware a severe hot water burn can occur in one second when the water is delivered at 60° C or higher. Hot water burns like fire because:
- At 60°C, a severe burn can happen in 1 second
- At 55°C, a severe burn would take 10 seconds
- At 50°C, a severe burn would happen after 5 minutes
What is a TMV?
TMV or thermostatic mixing valve installed by Whywait Plumbing
A TMV is a thermostatic mixing valve but is commonly referred to as a TMV. The role of a TMV is to mix hot and cold water together to provide you with hot water delivery at your tap that is at a consistent temperature.
When we install your TMV, we set the temperature to deliver the hot water in all bathrooms at 45°C in aged care or childcare facilities or 50°C in all other bathrooms.
A TMV is compulsory for use when used in common areas for aged care or childcare. A TMV is very accurate and very responsive to fluctuations in incoming water temperatures keeping the temperature to within 1° C of the temperature that it has been set at when we install it.
Accuracy of temperature in the TMV is delivered by a thermally sensitive element which expands and contracts in response to the temperature fluctuations of the incoming cold and hot water. This expansion and contraction regulate the temperature by controlling how much cold water mixes with the hot water. An added safety feature of a TMV is that if cold water flows become too low, they shut down to prevent 60°C plus water being delivered.
What is a Tempering Valve?
Non-compliant tempering valve installation connected with flexihoses replaced by Whywait Plumbing
A tempering valve’s role is also to mix hot and cold water together to provide you with hot water delivery at your tap that is at a consistent temperature.
The tempering valve is a simple three-way valve that is temperature actuated to mix the hot and cold water. These days most come preset at 50°C and when we install them, we test them by measuring the temperature of the water from your hot taps in the bathroom.
A tempering valve is commonly used in residential homes as a one-off valve at the hot water service. A tempering valve is slower to respond to temperature fluctuations compared to a TMV plus it will deliver water to within 3°C of the temperature that it has been set at when we install it.
Which Valve do you Require?
The Plumbing Code of Australia in AS/NZS 3500.4:2018 is very specific about water temperature is section 1.11, which states:
- To avoid the likelihood of legionella bacteria growth, an installation shall store water at a temperature of not less than 60°C
- All new heated water installations shall deliver heated water not exceeding 45°C for the aged, the sick, children or people with disabilities in healthcare, aged care, early childhood, schools and nursing homes. For all other situations, heated water shall be delivered not exceeding 50°C.
Ultimately when we are installing a temperature control device, we are legally obliged to comply with the requirements above and much more as they are prescribed in AS/NZS 3500.4:2018.
Overall a TMV is more expensive to install initially compared to a tempering valve. However, a TMV has a much longer working life span compared to a tempering valve as they are more accessible to service and replace the working parts. A tempering valve, by comparison, is usually just replaced when it stops working as they are not easy to service or replace parts in.
In Queensland, all work undertaken on a TMV or tempering valve is reportable to the QBCC and must have a compliant Form 4 submitted. For your protection always demand a copy of your Form 4.
Perception is reality and nowhere is this truer for us at Whywait Plumbing than when dealing with the issue of hot water temperature and the possibility of a serious hot water burn.
Everyone has a different perception of how hot they want their hot water whether it is for cleaning or sanitation or personal hygiene use.
Recent research in the United States from the Johns Hopkins Bloomberg School of Public Health, confirms hot water heater temperatures are too high.
In Australia, most manufacturers preset the thermostats for hot water heater temperature at 60-65 degrees. This is dangerously high for a significant proportion of homes, presenting a scald hazard particularly for young children and the elderly. This is because literally hot water burns like fire because:
At 60°C, a serious burn can happen in 1 second
At 55°C, a serious burn would take 10 seconds
At 50°C, a serious burn would happen after 5 minutes
It is estimated a serious hot water burn causes an estimated 1,200 hospital admissions and 50 deaths per year. Young children and elderly adults have thinner skin which burns more quickly putting them at increased risk.
In Queensland, it is the law that hot water delivered to bathrooms used primarily for personal hygiene purposes be regulated by use of a tempering valve or a thermostatic mixing valve that does not exceed 50°C. This is due to the fact that in 1995 the laws were changed requiring tempering valves to be installed on:
all new homes having a hot water system installed
replacement or upgrading of an existing hot water system
or when moving an existing hot water system to a new location on the property
However, homes built before 1995 will frequently still have hot water being delivered at 70°C. It is estimated that 37% of homes still have older electric or gas heaters delivering hot water that presents a scald hazard that will cause a serious hot water burn in one second.
Frequently these homes are rental properties. Many landlords and real estate property managers are unaware that recent litigation has placed a ‘deed of care’ onus on them to ensure the safe delivery of hot water in domestic bathrooms used primarily for personal hygiene purpose.
The installation of a tempering valve is an acceptable solution to hot water scald prevention. Delivering hot water at a consistent temperature is difficult without a tempering valve. This is due to the fact that as a hot water tank is depleted through use then replenished and reheated, the water temperature will not be constant throughout the tank.
Despite a perception by many people, a hot water service thermostat is not designed to provide precise estimates of water temperature. Its purpose is to begin heating when the temperature drops below a set level and turn off when it reaches a set level. Without a tempering valve installed it is almost impossible to assess the exact temperature of hot water delivered from a tap.
The advantage of a tempering valve is that guesswork is eliminated as tempering valves are designed to blend hot and cold water to deliver mixed water at a constant temperature and thus reduce the risk of a serious hot water burn.
Unfortunately for plumbers, property managers, homeowners and property investors hot water has increasingly become a legal minefield with the duty of care provisions.
It is for this reason Whywait Plumbing recommend that you install a tempering valve and maintain it compliantly with annual testing.
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