Flo-Rite Plumbing. Specialist in Hot Water Systems in Brisbane and the Gold Coast
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Hot Water Anode Replacement - Brisbane - Gold Coastnew and old hot water sacrificial anode

Anode Replacement – the easiest way to extend the life of your hot water system.

What is a Sacfrifical Anode?

An Anode is a magnesium rod that is installed inside your hot water tank and is the only thing that protects your tanks steel cylinder from severe corrosion resulting in premature tank failure.   
Every hot water tank comes with one and will only last about 4-5 years, but once your Anode is depleted
there is nothing to stop the destructive affects of corrosion on your tank - keep the tank you've got and
look after it, replace the Anode in it and it will last up to twice as long.
If your hot water tank is over 5 years old then you need to replace your Anode NOW!

You will save $$$ by making the hot water tank last up to 3 times longer.
You will save $$$ on electricity or gas when your tank is operating efficiently.
  • You will save $$$ on the hassle of frequent hot water replacements.
  • You will be helping the environment – less tank replacements.
  • You will put less pressure on our valuable resources - electricity, gas & water.
  • Your hot water will be much cleaner for use in the household.

We expose what Manufacturers don't want you to know and how you can add years to the life
of your Hot Water Tank saving you thousands of $$$

Why do Hot Water Heaters have an anode inside them?

Every brand of mains-pressure hot water storage heater with a vitreous enamel (glass) lined tank,
is fitted with one or two sacrificial anodes, to ensure that corrosion cannot take place during the warranty period of the tank.  

By simply replacing a water heater’s anode as required, (just when that is will depend on the size,
type and model of the water heater) the same protection is provided that keeps ships afloat,
underground steel pipelines and tanks corrosion free and even Australia's and the World's sea-based
oil drilling platforms intact.  That’s why the manufacturer put the anode there in the first place.

What causes corrosion?

Corrosion in water heaters is associated with the passage of minute electrical currents which travel through the metal and the water. 
Corrosion takes place at the anodic areas (the anode) which are the places where the
current releases ions to dissolve in the water.  Cathodic areas develop at other sites (the water tank walls)
where the circuit is completed and at these places, provided there is an effective anode working inside the
electric or gas hot water tank no corrosion can, or will, take place.  Anodes corrode - cathodes do not. 
Once the original anode stops working, the steel tank will react with any dissimilar metal, particularly
non-ferrous metals such as the copper element and brass plumbing fittings.  Once this occurs, the water heating
tank wall becomes anodic and corrosion (rust) commences and the hot water system will very quickly rust through.

How do Anodes work?

Anodes are manufactured from a special grade of magnesium and they protect steel by a sacrificial
electro-chemical action.  Magnesium is electro-negative relative to steel.  When a magnesium rod is fitted to a
steel hotwater tank filled with fresh water, a current will constantly flow through the water between the rod
and any exposed steel area on the tank wall.  The circuit is completed through the tank back to the magnesium rod. 
This protective current is produced by the magnesium releasing ions, and this results in corrosion in the anodic
area.  This type of rust protection is called “sacrificial”. The magnesium (the anode) corrodes instead of the
steel tank (the cathode).  This principle of electrolytic corrosion control is called cathodic protection.  
Because cathodic surfaces cannot rust, the  hot tank is protected.

This principle is nothing new.  No experienced boat owner would risk the propeller, rudder, shafts or other
exposed metal equipment on his boat, when all it requires to ensure that they do not corrode, is to keep an
effective sacrificial anode in place on the hull of the craft or on the motor itself in the case of outboards.  
The same system is used on all commercial shipping, oil drilling platforms as well as underground pipelines and
storage tanks.  It’s far more economical to replace the anode than to allow the vessel itself to corrode.  
This logic also applies to domestic and commercial  hot water heaters.

What about older heaters?

The older a water heater is, the greater the likelihood of it having little or no remaining active anode and at the same time, having experienced an appreciable deterioration of the "glass" lining, thus leaving areas of' exposed steel wall where corrosion may have already started.  While that corrosion cannot be reversed, it can certainly be arrested by the introduction of a new anode, which can get to work by reversing the electrical flow and converting the hot water tank wall back to a cathode (parts of it will have become anodic after the original anode ceased operating).

Once there is any discolouration of the hot water, the water heater is usually too badly rusted to be saved by fitting a new anode.  

Original equipment replacement parts.

The sacrificial anodes Flo-Rite Plumbing supplies and fits are manufactured by the same company which supplies anodes to the heater manufacturers themselves.  They are genuine, original equipment anodes and will therefore not void manufacturers' warranties.  They are manufactured to exacting standards as laid down by Standards Australia and are approved by every water authority in Australia.


All gas hot water, electric hot water and solar hot water mains-pressure water heaters with a vitreous enamel or bonded ceramic coating utilize a sacrificial anode to provide additional corrosion protection.

RHEEM, BEASLEY and QUANTUM  solar heaters.  



These are mostly found in older homes and they are rarely supplied new nowadays due to the fact that the hot water supply relies on gravity alone and as such, it is not very satisfactory for showering.


Instant hot water systems are small, wall-mounted instant water heaters which heat the water continuously as it passes through them.  Common brands are BOSCH, PYROX, ZIP, RINNAI Infinity, BAYARD  and RHEEM Integrity.


These water heaters look similar to the ones that do require an anode.  They are generally the same size and shape but the hot tank is either stainless steel or copper and does not require an anode. Brand names to look out for with a stainless steel tank are AQUA-MAX gas heaters and EDWARDS and BEASLEY, in both electric and solar types.  
Heaters with a copper tank include SAXON COPPERFLOW and RHEEM COPPERMATIC.  These copper tanks are no longer available due to the high cost of manufacture.  There are probably some other, less common brands still in service, so check the specification label and other information printed on the hot tank in order to correctly identify the type of water heater.


For  water heaters in the BRISBANE and GOLD COAST area, the anode should be inspected as close as possible to the times detailed above. Under average conditions, it is normal that an anode will require replacement at these times. Even if there is apparently still sufficient magnesium left, it is often heavily coated with mineral deposits and it is therefore unable to provide effective protection for the heater’s tank.

All sacrificial anodes, when manufactured, were extruded onto a central core of 3mm diameter mild steel wire. Thus, as an anode corrodes away, it progressively exposes that wire core.  Generally speaking, the sphere of influence of an active anode is approximately ten centimetres (four inches). Thus, if the amount of exposed wire at the top or bottom of the anode exceeds this amount, it is safe to assume that that section of the heater's tank
is no longer receiving protection from that anode.

We have found that anodes fitted to Rheem hot water heaters and Vulcan hot water systems wear more at the top and those fitted to Dux hot water heaters (previously Hardie Dux) are more inclined to wear at the bottom. This creates a situation when checking Dux heaters where there is insufficient headroom to fully remove the anode to inspect the bottom.  It cannot be assumed that the anode is still OK just because it is solid at the top.  
In this situation, it is best to follow Dux's recommendation and replace the first anode at five years or, at the very latest, as detailed in our timetable above.  For the benefit of installers, you can judge the amount of wire core exposed at the bottom by tapping the anode against the inside wall of the tank.


Most water heaters have an identifying sticker, or label, detailing the heater’s capacity, model and serial numbers plus other technical details relating to its operation.  This sticker will show the date of manufacture of the heater and a close estimate of when it was installed will be two or three months after this date. If the sticker has faded or been damaged, you will have to check back on receipts or ask the previous owners of the home.  If it's not possible to determine the age of the hot water system, then a water discolouration check and an inspection of the anode is the only way to determine the remaining life of the heater.

The identification label on Rheem and Vulcan cylindrical electric and indoor gas heaters is located around the top of the heater. Dux electric heaters have the label in the middle of the heater at the front. Square outdoor gas heaters have the sticker located inside the pilot light cover plate.


Many  water heaters are installed indoors in the garage or laundry, or under the eaves on the outside where there is insufficient headroom above the heater to remove the old anode and fit the replacement. In these cases, the old anode is removed by cutting it in sections and the replacement anode is a specially developed flexible type. Nevertheless, a minimum amount of space above the heater of 35 to 40cm is required to fit the new anode.


Most water heaters BRISBANE and the GOLD COAST last around 7 to 15  years. There are always exceptions and we have seen heaters 20 or more years of age which are still providing good, clean hot water. On the other hand, we have also seen water heaters which have rusted through at 4 or 5 years of age. Obviously both extremes are quite rare, but they do happen. Experience has shown us that, once rust gets started, it takes about two years for it to eat right through the tank wall. Therefore, the average heater only starts to rust at the 7 or 10 year mark. For this reason, we have set a limit of 10 years for replacing anodes in standard model heaters, after which we are reluctant to replace the anode. Again, exceptions are sometimes made when the heater looks in good condition and where the anode is still working. (That is when grey metal is clearly visible, indicating anodic reaction is still taking place.)  Water quality is tested and if there is no discolouration, the anode will be replaced.

OUR ANODES HAVE A MONEY BACK GUARANTEE If the water heater fails within 12 months of the replacement of the anode, we simply refund the cost of the new anode off your new tanks installation. Once the heater has lasted twelve months, we know that we have replaced the anode in time before the rust has gone too far and that the hot water heater can be expected to last the life of the new anode. This guarantee does not apply to anodes sold on a supply-only basis where we have not had an opportunity to inspect the water heater prior to installation of the anode.

Contact us with an Online enquiry or call us now on Brisbane 1300 785 989 or Gold Coast 07 5536 8043


Flo-Rite Plumbing Brisbane Gold Coast