Hi all, my system has a copper feed and expansion tank as originally supplied and fitted in conjunction with a Boilermate 2. The F&E tank has started to leak, it has a series of pin holes in it, any idea what would cause this? I'd understand it it was a ferrous metal or an old galvanised tank, but it's copper. Thanks
Copper feed and expansion tank leaking
- Thread starter elevonic
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Better if you post pics
Possibly galvanic or chemical/acidic, that material has thinned out considerably. The fact that it's a F&E for a thermal store may lend itself towards corrosion, they are known for it, has the thermal store/system water been checked and is it well inhibited?
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What was the store replaced with? You don't happen to have stainless steel connected to the copper anywhere? There really are only 2 ways copper will 'corrode' to that degree and that's galvanic/electrolytic or acidic.
I believe the replacement store is stainless, interesting.
Copper can corrode if directly connected to Stainless Steel (S/S) (iron) especially in an acidic environment if there isn't a dielectric connector in place, that can then cause a galvanic (electrolytic) reaction.
Usually though S/S cylinders like unvented ones either incorporate dielectric tappings, incaloy coatings or sacrificial anodes to avoid corrosion as CH systems are notorious for being a mixture of different metals. That being said something has obviously corroded that vessel.
Usually though S/S cylinders like unvented ones either incorporate dielectric tappings, incaloy coatings or sacrificial anodes to avoid corrosion as CH systems are notorious for being a mixture of different metals. That being said something has obviously corroded that vessel.
Ouch that looks expensive
It would be much more expensive or damaging if we hadn't noticed the slight drip from it and that hole appeared flooding the house!
Do you still have a thermal store? What is in place as a F&E for it now, standard cistern? I presume it's been changed for something more suitable?
Couple of bucks in that vessel if it's copper
Couple of bucks in that vessel if it's copper
Do you still have a thermal store? What is in place as a F&E for it now, standard cistern? I presume it's been changed for something more suitable?
Couple of bucks in that vessel if it's copper
Yes, still got a thermal store, system is drained down so I could remove the leaky F&E. I contacted Gledhill about a replacement copper one and they have said I don't need a copper or metal one as they are used for uncontrolled heat sources not a conventional gas boiler system with thermostats etc. Polytank looking like a suitable replacement as in their words "All our tanks are primarily used as F&E cold water tanks. They are boil tested for 500 hours to BS4213 but are not suitable for solid fuel systems as the temperature cannot be regulated".
If you system is just running of a standard CH boiler then a plastic F&E should be fine. If the heat source is uncontrolled, as suggested, that's when it would require a metalised cistern to be able to withstand possible excessive temps.
That's a little more than a 'pinhole'
That's a little more than a 'pinhole'
That’s the result of seeing a few pinholes and then prodding them with a finger! Lol
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