Open vented stainless cylinder immersion problem?

[Agile]

This problem only relates to stainless OV cylinders!

They recommend Incoloy immersion elements because copper is attacked first and can corrode within a few months in some cases.

BUT Screwfix and possibly others are selling incoloy elements with a COPPER thermostat pocket.

Has anyone here experienced this problem yet?

Tony

 

[Boilerman2]

I have known Immersion stat pockets to fail, but you make a very good point that would be worthy of taking up with the manufacturers Tony!!

 

[steve32]

I only fit titanium immersion heaters so never had a problem.

Have a read of this

http://www.plumbingpages.com/featurepages/HWHRtitanium.cfm

Steve

 

[swbjackson]

Plumb Center are also selling incaloy immersions with a copper pocket with stainless cylinders. They are available with stainless pockets as a local independent keeps them in stock.

 

[DeltaT2]

Very interesting thread as OV stainless HW cylinders are about 30-50% cheaper than copper.

 

[Agile]

My interest started because I bought three stainless OV cyls recently and was reading the installation instructions asking for incaloy immersions.

I then telephoned the makers and asked about the failures which was interesting. But they have only been making their cylinders for only a short time so dont have much practical experience. But he said that in effect any copper in a stainless cylinder becomes a sacrificial anode!

I have since found that toolstation are selling the same one as Screwfix using the copper pocket. To me the risk of an element failing is of little importance because its not going to do any damage.

A failed pocket can potentially leak water through several floors and do thousands of pounds worth of damage.

Those titanium elements with a five year warrantee look like the best solution!

I will email the makers of the Screwfix ones for their comments. I suppose they are importing Chinese made goods and just want a cheap unit to satisfy the sheds without considering the consequences. I believe they should print a warning about using them in stainless cylinders.

Tony