In article ,
Christian McArdle wrote:
Really? Think if you did a straw poll on here of previous posts you'd
find far more about faulty pressurised systems.

These days, I would think that a significant majority of installations
are of the sealed, pressurised type.

I'd agree, but being newer why so many problems?

Also, we are talking about energy efficiency. Faults in a sealed system
largely result in failure to work at all.

Many typical faults in an open vented system result in the system working
inefficiently, due to such nasties as pumping over, leaving a header tank
full of hot water.

That's not so much a fault as poor design.

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Dave Plowman London SW
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