Electric hot water systems are by far the most common sort of hot water heaters in the Australian home. They have been made here in Australia for over 100 years,. The technology hasn’t changed much over this time, just different materials are used and with thicker and denser insulation around the storage cylinders, this holds the temperature within for longer periods of time, therefore having less heat loss equals slightly better efficiency from electric hot water systems manufactured prior to 2000.
Working the same as a kettle with a heating element, they come in 3 different power ratings for the Queensland market, 1.8kw, 2.4kw and 3.6 kw (some areas have 4.8kw elements but few and far between in Queensland due to the draw of power required). This is the same throughout all brands like Rheem, Dux, Vulcan, AquaMAX, Rinnai electric hot water systems
Having different size elements does not equal different energy ratings, for example a hot water heater with a 1.8kw element (1800 watts) will use half the power as a 3.6kw (3600 watt) element but will take twice as long to heat the same body of water to the same temperature.
Electric hot water system are manufactured out of mild steel tanks that is vitreous enamel lined internally and protected by a sacrificial anode and stainless steel, They old copper style water heaters are no longer available
An electric hot water system generally will equate to at least 1/3 of your power bill when you don’t have P.V solar usage and sent back to the grid for a buy back price on your tariff 11, which is what your general power and lighting are connected to, to supply power 24 hours a day at a cost higher rate. Your P.V solar power, should you have it will not help or power a hot water heater when it is connected to tariff 33 which is an 18 hours a day power guarantee and normally will be on expect for 6pm to 9pm and 6am to 9am or tariff 31 which provides power only during the lowest draws on the electrical grid and generally is between 9pm and 6am.
Tariff 31 will not provide enough power for hot water cylinders below the size of 250 litre when for 2 or more people
Electric hot water systems come in tank sizes that range from 25 litres that is used for kitchens and single sink applications right through to 400 litres
Below is a approximate person to size recommendation.
There may be slight variations due to the amount of hot water used by occupants
50 litres & 80 litres = 1-2 people in a unit type home and only connected to tariff 11 and can not be connected to a off peak tariff to provide reliable hot water
125 litres = 2-3 people in a unit or small town house, when connected to tariff 33
160 litre = 2-4 people in a unit or small town house, when connected to tariff 33
250 litre = 2-4 people when connected to tariff 31 and is what is in most 3 bedroom homes built and up to 6 persons when connected to tariff 33
315 litre = 3-5 people when it is connected to tariff 31 and up to 7 persons on tariff 33
400 litre = 4-7 people when connected to tariff 31 and up to 9 people when it is connected to tariff 33 and 12 people on tariff 11
Brands of Electric Hot Water system available
Rheem hot water heaters by far have had the largest running advertising program and are a recognised name worldwide for hot water systems.
Rheem manufactures a large range of electric hot water heaters in Australia, Sydney for their mild steel Vitreous Enamel (VE) range and Melbourne for their stainless steel products, in what was previously the AquaMAX hot water systems factory
Rheem has a large number of known domestic hot water brands under their banner like AquaMAX, Vulcan and Solahart
They have warranties that vary between 5 yrs to 12 years depending on size and product made from and require services at no more than 5 year to support the warranty and prolong the life of the hot water tank by the changing of sacrificial anode in the VE range and also recommended the pressure and temperature relief valve changed as well
The AquaMAX name has been around since 1988, they were a family owned business until Rheem brought them in 2009, AquaMAX had by that time sold over 500,000 electric water heaters
AquaMax has always had the name amongst the industry as quality especially with their Stainless Steel products
Their Stainless steel products are still made in victoria and the mild steel VE electric hot water range is made in Rheem’s Sydney plant
The AquaMAX hot water range come with warranties between 7 years and 10 years depending on the size of the cylinder, the smaller it is the less the warranty
They require a service prior to 5 years of service especially changing the anode to help the tank last longer
Vulcan electric hot water systems is another brand owned and manufactured by Rheem hot water systems
Vulcan only make their electric hot water range in the mild steel Vitreous Enamel style.
The Vulcan 50L Electric Storage water heater has a 7yr cylinder warranty and the Vulcan Electric 80 litre through to the 400 litre carry a 10 year cylinder warranty
They require the anode to be change between the 4th and 5th year of use to prolong the life of the cylinder
They are generally recognised as Rheem’s budget brand
Rinnai has for a long time been a name in the gas hot water industry and until recently had sourced their electric hot water range from China &/or Dux hot water manufacturing in NSW
They have now opened their own manufacturing plant in Victoria for their Hotflo electric hot water systems
Rinnai electric hot water systems also come in sizes that range from a small kitchenette type 25 litre system right through to the massive a 400 litres
The warranties are 7 years on the 25 and 50litre systems and 10 years on all above that, but do require a 5 year or sooner service to last the distance and carry the warranty
Dux hot water systems have been around in Australia for over 100 years and until a few years ago was Australian owned.
Dux only make their electric hot water systems with mild steel vitreous enamel lined cylinders
Dux electric water heaters are manufactured in Moss Vale NSW and China with their tanks ranging from 25 litres up to the 400 litre big one
The warranties vary from 7 years on the cylinders of the 25 and 50 litre systems to 10 years all above that capacity
Like all other mild steel hot water systems they have sacrificial anodes and require changing prior to the 5 year mark to last and have the warranty honoured
Since Dux was sold their name in the hot water industry has fallen from Australia’s #2 brand to lows that no one would want their business to become.
They have really only survived due to supplying Bunnings and making the Therman brand for Reece Plumbing Supplies, no other place bothers to stock or sell the Dux brand anymore
Thermann electric hot water heaters is a brand name that is exclusive to the Reece Plumbing Supplies chain
The electric Thermann hot water systems are manufactured by Dux Hot Water in New South Wales and China for the smaller storage capacity heaters
Being the exact same system as the Dux Proflo, except the stickers saying what they are, they come in water storage sizes of 25lt, 50lt, 80lt, 125lt, 160lt, 250lt, 315lt and 400lt
Made from mild steel with a internal vitreous enamel coating they have the sacrificial anode protecting it from deterioration that need replacing within the 5 year period
They come with the same warranty periods as the DUX Proflo of 7 years and 10 years
These electric water heaters are nothing fantastic just a re-labelled system of a brand that has lost its way in the industry with poor products, after sales, warranty and a very low care factor for consumers
Thermann water heaters are only available at Reece Plumbing Supply stores