Replacing your vitreous enamel hot water cylinder anode could extend the life of the cylinder.
Decent shower pressure is one of life's pleasures. Mains-pressure hot water systems have largely taken over from low-pressure systems that used copper cylinders.
Most mains-pressure hot water cylinders today are made from steel that’s lined with a vitreous enamel – much like the inside of ovens.
If the enamel has any manufacturing imperfections, the exposed steel could rust. To stop that happening, all vitreous enamel cylinders have a replaceable metal anode installed in the top of the cylinder and in contact with the water. This anode “sacrificially” corrodes instead of the steel cylinder.
How quickly the sacrificial anode erodes also depends on the local water quality. The quality of our reticulated water is generally high, but if it has been poor during the life of the cylinder then the anode can erode prematurely.
Replacing the anode before any damage is done could extend the life of the cylinder. But how can you tell if your anode needs replacing? The only way is to remove it and take a look at its condition.
Tip: Ask a reputable local plumber if premature failure of mains-pressure cylinders is a problem in your area. If it is, get the anode checked – and replaced if necessary.
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We have just had our cylinder moved as part of our home extension. The plumber who moved it was a young German chap who told me he should check it as the cylinder was 8 years old. He said it normal in Europe to check the anode every few years. His boss however (A Reputable Plumber of many years standing) had never heard of a sacrificial anode ans was not really interested in the fact that they prolong the life of the cylinder. I guess he figured it better sell a $1500 cylinder than a $100 part.
I suspect a lot of plumbers have the same attitude or are completely ignorant of what the anode does.
We have a Rheem 180 litre high pressure electric water cylinder that was installed new when our house was built in 1983. By all accounts, it should have failed years ago, and I never knew there was an anode to be replaced. We're on the North Shore. Are all areas of NZ affected by this, or only areas with dodgy water? What now? Should we risk fixing what hasn't broken yet?
Hi David,
If the water cylinder has not failed yet, that is a sign the water quality is good. Ask a reputable local plumber if the anode should be checked.
Kind regards,
Bill Whitley
Writer
I have a Coopers "Economiser Super", 180 Ltr hot water cylinder with the DOM of 29/8/01 on it.
It also has a metal "seal' that states it has a "copper 7mm body".
I looked at the top and all around the cylynder , but couldn't see an anode anywhere.
I noticed that there was an owners leaflet still attached to the cylinder and it made mention of "if" it had an anode ( hydrogen gas) and also in regard to "blue water" as a reaction with the copper.
Would this type of cylinder have an anode in it, ad if so, where is it??
Does this apply to both gas and electicity hot water cylinders? The article doesnt mention this point. I thought gas cylinders had a glass liner?