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

 

[Dan Robinson]

Not quite the same, but we have a building with 20 odd Range unvented SS cylinders with sensor pockets that are coated copper (don't know what it is, maybe chrome).

Several have corroded through causing varying degrees of damage to the building. We were issued with SS slugs to replace them with.

Manufacturer refused to accept liability claiming Chlorine caused it. It is possible that the company that flushes the cold water tanks doesn't rinse the chemicals out properly, but the other pattern was the flats worst hit had the lowest occupancy. So the running theory is that some water with a higher than normal chlorine level is drawn into the cylinders. The empty/emptier flats then have that water sitting in them eating away at these rubbish components.