With steam or hot water heat there is a slightly larger temperature swing between cycles. The heating medium being water takes a little longer to absorb the heat from the exchanger. The new tube type systems are far more efficient than the older cast iron models but air will always heat faster than water.
Since you do not have the dry air with steam as you do with the forced air systems the fluctuations are not as noticeable. Your boiler will be far better off with the larger temperature swings.
This is the edited part. The tube type boilers are only available for hot water and not steam, as far as I am aware. Sorry for the inaccuracy.
[ 12-18-2005, 10:26 PM: Message edited by: plumber ]
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