What is an Anode? | How To Replace Anode in Hot Water System
Replacing your Electric, Gas & Solar hot water systems Anode
What is an Anode?
An anode is a highly reactive metal component inside your hot water system which protects it from corrosion by attracting electrolytes more strongly than the rest of the hot water system.
If you want your hot water system to live longer, Moyle Plumbing & Gasfitting strongly recommend a routine replacement of the sacrificial anode inside your hot water system every 5 years.
What is a sacrificial anode?
Most tank-based hot water systems feature a, ‘sacrificial anode’.
A sacrificial anode is a metal rod, normally made from aluminium or magnesium, and coated in zinc, which is installed inside your hot water tank.
The sacrificial anode is designed to attract minerals and impurities in the water which would otherwise react with the inside of the tank and cause it to rust and deteriorate.
This ‘sacrificial’ rod slowly rusts and degrades, sacrificing its own life for the greater good of your hot water tank.
Why do Hot Water Systems have an anode?
Every brand of mains pressure hot water storage heater is fitted with one or two sacrificial anodes.
This ensures that corrosion cannot take place during the warranty period of the tank.
What causes your anode to corrode?
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 the 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.
Why should an Anode be replaced regularly?
The anode sacrifices itself to protect the rest of the Hot Water System. In most cases (and depending on the properties of the water where you live), sacrificial anodes need to be replaced once every 5 years. Regular replacement of the anode may extend the service life of your hot water tank by five to ten years.
How to Replace Anode in Hot Water System?
Replacing an anode is not a job you should carry out yourself. Hot water tanks contain scalding hot water and steam and are connected to the electricity or gas supply.
This work should only be performed by a licensed and experienced plumber such as, Moyle Plumbing & Gasfitting.
If there were a way you could safely carry this job out yourself, we would provide you all the DIY steps you need to know, but in this case, it’s simply not advised.
How does a sacrificial anode work?
Corrosion or rust is the result of electrolytic action which travels through the water and reacts with a surface of the metal at risk.
A sacrificial anode works by attracting electrolytes more strongly than the rest of the hot water system, keeping other system components out of harm’s way.
As well as hot water heaters, sacrificial anodes protect ships at sea, pipelines, boilers and other steel structures that are under water or in damp soil conditions where risk of corrosion exists.
Anodes are made from a special grade of magnesium and they protect steel by a sacrificial electro-chemical action. Magnesium is electro-chemical action. Magnesium is electro-negative relative to steel. When a magnesium rod is fitted to a steel hot water tank 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 protections is called, ‘sacrificial’. The magnesium anode corrodes instead of the steel tank .
Does your Hot Water Tank need it’s Sacrificial Anode replaced?
Call Moyle Plumbing on 07 3807 7327 for hassle-free sacrificial anode replacement.
Replacing the sacrificial anode is the easiest and most cost-effective way to extend the life of your hot water system.
Moyle Plumbing & Gasfitting are experts in the replacement of all types of hot water system sacrificial anodes and can provide honest advice on all aspects of your hot water system servicing.
Extend the life of your hot water system by calling Moyle Plumbing & Gasfitting for a qualified experience hot water plumber.
We offer same-day service and charge no call-out fee.
Richard Moyle
Founder of Moyle Plumbing & Gasfitting. Plumbing for his local commi=unity since 1983