life expectancy of copper hot water cylinder

[fred]

We are having to replace a copper hot water cylinder for the second time in 25 years. Does this sound normal. Anyway what makes them fail. We are in a soft water area.

[newshound]

Because of corrosion?

Modern ones are certainly thinner than older ones, but ~ 10 years sounds short. If the failure occurred in the same area I would be wondering about some concentration of corrosive products, or a "dissimilar metals" problem.

When you say a soft water area, I believe water from peat areas is relatively acidic, which might not help.

More details needed!

[harry]

The water company is supposed to treat any acidic water so it doesn't affect pipes and cylinders. Get some narrow range litmus paper and check your water. If it is acidic complain to them. Don't forget, every pipe in your house may be corroding away. Could have a flood and major expense.

[michael adams]

If its anything to do with the water, then wherever you buy the replacement, assuming its fairly local might be able to put you straight. Either them or any neighbours.

michael adams

...

[F Murtz]

You are probably supposed to replace a sacrificial anode after 5 years, All our mains pressure copper water heaters have them but I have never seen anyone replace them.

[harry]

You could get a stainless steel replacement. However,all your pipework may be similarly affected. This is an advantage of plastic pipes over copper.

[Dave Plowman (News)]

Under most circumstances, copper will last a lifetime plus. Too early to say if plastic will. I'd guess not.

[CB]

I have lived in this house since it was built (1987). Just about every house in the close had its hot water tank (all unpressurized) replaced when the houses were 12-15 years old. Although this of course may have been a faulty batch. We are now approaching the end of the second life period so I hope that the replacement I fitted was of higher quality.

They all failed at the cold water entry point so I don't know if this was an area subject to condensation caused corrosion or a manufacturing fault.

This is not a soft water area.

[Windmill]

That has been my impression. Perhaps insurance companies stick in an oar to try to improve life expectancy of copper tanks (vitally important for the many flats in the UK).

I was amazed by the short life (~10 years) of what they describe as 'glass-lined steel tanks' in Canadian gas heated homes.

Had to replace one after only a few years, but luckily at that time I was still allowed to do the work myself. Probably no longer possible even there, due to "elf an' safety", but when I visited the house 15 years later, the purchaser was still there, had no complaints, and the house hadn't blown up.

I just hope the short-changers don't try the same tank life scam here.

[harry]

The corrosion is caused by dissolved CO2. As the water is heated, it is driven out. So corrosion takes place at the cold entry point. It's not a galvanic thing, that only happens where there are dissimilar metals. The sacrificial anode only protects against galvanic reactions.

All rain water is acid (dissolved CO2). In some places the acidity is corrected when the water runs through limestone or chalk. In others not. Peaty areas are the worst.

[thescullster]

I had one fail after only a few years (maybe 6).

When I was tying up the ball float in the cold water tank in the loft, I noticed something lurking on the bottom. Turned out to be a pair of very corroded steel pipe grips. Guess these will have been the cause of the short lived anode's demise.

Phil

[John Smith]

[John Smith]

[John Smith]

[Jack Harry Teesdale]

Failure after 6 years is not 'normal'.

However it depends on the cause of the failure, which you seem to have identified in this case.

As long as there is no inherent manufacturing defect, in a soft water area you could expect 15 to 20 years or more, but que sera, sera.

[jon]

My copper cylinder that delivers mains pressure hot water has been in place 27 years.

[Brian Gaff (Sofa]

2015? Anyway, I'd expect30 years pluss assuming its not a bodgit and run one of course! Brian

[Brian Gaff (Sofa]

What is going on with these old posts?

Brian

[Harry Bloomfield, Esq.]

jon laid this down on his screen :

Open vented and my cylinder is 38 years old.

[Jack Harry Teesdale]

Older tanks were made of thicker gauge copper so tend to last longer.