Weil McLain hydronic boiler water feed question
- Thread starter Enosez
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rjbphd
In the Trades
No! Best place for boiler feed is at ponpc connection.
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Enosez
Member
What is the ponpc connection?
Do you mean at the air scoop inline with the expansion tank?
I looked that up: point of no pressure change. http://smartgreenbuild.com/blog/download/591/ is a PDF.
Seriously "ponpc"- is that an acronym ANYBODY in the industry uses? 
(I've not encountered it even in Ziggys other scribblings.)
As long as you fill the system when the pump isn't running it doesn't matter at all where the feed point is relative to the expansion tank or pump.
But it's a bad idea to feed cold water into a hot system right at the cast-iron casting, where it might enter a hot boiler at a radically different temperature, which puts the heat exchanger plates under considerable mechanical stress, and can even crack a plate. It's better to put it on the plumbing on the output side of the boiler, not on the boiler itself. If the feed is right at the boiler, only fill the system when the system is cool or tepid, say under 100F.
(I've not encountered it even in Ziggys other scribblings.)As long as you fill the system when the pump isn't running it doesn't matter at all where the feed point is relative to the expansion tank or pump.
But it's a bad idea to feed cold water into a hot system right at the cast-iron casting, where it might enter a hot boiler at a radically different temperature, which puts the heat exchanger plates under considerable mechanical stress, and can even crack a plate. It's better to put it on the plumbing on the output side of the boiler, not on the boiler itself. If the feed is right at the boiler, only fill the system when the system is cool or tepid, say under 100F.
Enosez
Member
Thank you
