What is a Hot Water Anode?

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What is a Hot Water Anode?

Anode Rod

A hot water anode or “sacrificial anode” is essential in keeping your hot water tank in its best condition and extends the lifespan of your water tank, as it prevents corrosion of the tanks. Your water heater is one of the most hard-working appliances in your house. Whilst it is a quiet achiever it’s no doubt bringing you the comforts of the modern era, imagine life without one.

As a Plumber I receive calls every day from people who require a hot water heater replacement, this replacement is often being done prematurely due to the fact that they have not serviced and replaced the sacrificial anode on their water heater.


Are steel core rods surrounded with either magnesium, aluminium or zinc and are installed on the top of hot water tanks. It’s similar to sacrificial anodes used in various types of vessels such as ships, barges, tankers and also used around docks and harbours. Through a process called electrolysis the “sacrificial anode” will corrode in place of the heater’s exposed steel. This happens whenever metal needs protection from the water and occurs when two pieces of the submerged metal react to the voltage.

During this process the more reactive metal Zinc, magnesium or aluminium will corrode before the less reactive metals like copper and steel. These metals acts as a kind of protection for the heater. Anodes should be changed every 3-4 years but would vary on the quality of water on different areas. Once fully corroded, the anode will cease to protect the tank, which will become a problem if left uncorrected.

Sacrificial Anode

It is highly recommended to have these anodes replaced as soon as they get fully corroded to prevent expensive tank replacements prematurely.

Water heaters generally have a lifespan of around 10 years, however, this lifespan can be increased if you replace your water heater’s sacrificial anode at the recommended intervals, As plumbers, it’s our professional obligation to advise you of ways that can assist in giving you longevity of your entire plumbing system. What I find is that more often than not we don’t educate our customers enough on the benefits and hazards that surround their plumbing products and systems.

Next time that you have a plumber at your house, for whatever reason, please be sure to ask him about your water heater and have him check the condition of your water heater’s sacrificial anode, this will take him no time at all and may save you money and more importantly the inconvenience of having no hot water or even worse a leaking hot water heater.

It’s surprising but water heaters tend to stop performing at the most inconvenient time, like when it’s freezing cold, or start leaking when you’re not around to see it and therefore can cause serious damage to your property. Take my advice and get your water heaters checked at least every 5 years. Hence get in touch with The Doctor for reliable anode check and supply.

Electric Hot Water System

What Type Of Water Heaters Have Anodes?

Storage water heaters that are not stainless steel will have anodes that require replacing. This includes all electric and gas models. For your hot water needs don’t hesitate to contact us anytime. We serve areas in Canberra, Newcastle, Hunter Valley, Central Coast, Lake Macquarie & Port Stephens. So if you’re in the middle of making a hot water decision, give us a call at 131091 were open 24/7 or visit our website.


General Plumbing & Electrical, Hot Water Systems, Blocked Drains, Gas Fitting