Circ pump installation


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Old 02-14-09, 07:24 AM
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Circ pump installation

Is it preferable to install the circ pump in the supply or return of a hot water system? I am installing a new boiler. My old boiler had the circ pump in the supply, before the zone valves, but i've heard that it is better to install the circ pump in the return line. Any help would be greatly appreciated.
 
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Old 02-14-09, 07:31 AM
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Either supply or return MAY be correct. The key is to have the pump's suction just downstream of where the expansion tank ties in.
Doug
 
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Old 02-14-09, 08:32 AM
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In the absence of explicit instruction to install the pump on the return side (some do require this, check install manual) I would install on the supply side, as Doug says, 'pumping away' from the expansion tank connection.

What boiler are you installing? Tell us a little about your system.
 
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Old 02-15-09, 05:16 PM
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Pumping away from the expansion tank is the proper application. The supply side of the boiler assists in air elimination as heating water helps drive the air out. For more info see this link.
http://www.comfort-calc.net/pictures...old_Piping.JPG
 
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Old 02-15-09, 05:37 PM
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When the pumps are on the supply side where do you install the flow checks, and how is system bleeding effected?
 
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Old 02-15-09, 05:49 PM
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Originally Posted by happyhomeworker
When the pumps are on the supply side where do you install the flow checks, and how is system bleeding effected?
When the flo-control valves do their business (i.e., stopping gravity flow), the circulator pump is off.

Is there just one zone? Then the flo-control valve can go anywhere, but you will need one in each header. If there are mulitiple zones, it gets more complicated.
Doug
 
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Old 02-15-09, 06:24 PM
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I have five zones all on circulators. I have trouble with 2 zones that are always needing bleeding. This summer I'm planning on moving all the circulators to the supply side (they are on the return side now), and am confused as to where I would put the flow checks.
 
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Old 02-16-09, 05:01 AM
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Look at the link I posted. It shows them after the circulator.
Flow checks and flow control valves are the same thing.
 
 

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