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Dave Liquorice
 
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On Thu, 18 Nov 2004 18:37:09 GMT, ARWadsworth wrote:

How does this work? Gravity fed CH systems have no stat on the tank.


I guess there are such things as gravity fed CH systems but they must
be close to hens teeth in rarity value... Gravity fed HW however is
very common.

You have a tank stat because you don't really want your HW at the 80C
that you really need for the CH circulation, scalding risk. You fit a
tank stat to a) stop the boiler cycling to keep the gravity loop hot
once the water is hot enough b) control the temp of the HW when there
is no CH demand. Of course when the CH calls for heat the HW temp will
rise above that of the stat, that is a failing of the gravity system.

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Dave. pam is missing e-mail