Hot water cylinder scale

[rktatschner]

Is there any way of telling if a hot water cylinder has a scale problem before trying to remove the top fixture. This is one of those fully foam insulated ones so tapping on the cylinder does not produce the reassung clang.

 

[Bahco]

A hot water cylinder has a sacrificial anode in the bottom of it which is attacked instead of the cylinder.
I believe it is made of a weaker metal called magnesium and has been proven to protect the cylinder so you may be worrying unduly.
However if your cylinder is very old and there are visible signs of corrosion its time to renew

 

[ChrisR]

Scale is unlikely to be a problem unless you live in a very hard water area, in which case it could fill your cylinder eventually. Main symptom is noise from the immersion heater and lack of HW volume.
Much More likely to get it if the thermostat is set above a critical temperature I can never remember - about 62C.

The sacrificial anode is there to stop the copper corroding - which happens more in soft water.

When I take them out I leave them on the pavement and somebody usually obliges by carting them away on a roofrack - they're only worth a few quid so not worth carrying far. But if they're full of scale they weigh a ton, so inexperienced scrap dealers think its really thick copper and get pitiably enthusiastic.

 

[Bahco]

Chris
I weighed one in last week and got £14.
Let me know when you are working in the West Midlands

 

[AdamW]

Give it to some new-age hippy types. They love their copper jewellery and accupressure copper insoles, why not a big copper cylinder? They could clean it out and store their hippy strawberry wine in it perhaps. The acid (in the wine, not the other type!) would cause considerable corrosion though...