Taco 007-IFC

Mark Mathys

I know this is a dumb question but I need help.

How does the Internal Flow Check valve work in this pump? or more specifically which direction does it block flow? I need to stop heat flow from going in the same direction I want to pump unless the pump is on. It is my understanding that this is what the IFC does but I want to make sure.

thanks
Mark

Weezbo

the top of the morning to you.

scott337

Clarify Please

Is the heat migrating through the "off" circulator to a different zone that is calling?
I have hear of this and it has to do with near boiler piping and balancing. get more info please

Kal Row

internal checks on both taco and grundfos are springchecks...

and as such, should be closed when circ is off,

but, (the big but), unless you system is spotless, and water is not hard - it's probably not closing too well in the flow direction - and you could get gravity convection if the temp difference is big enough

do you feel the heat migrate with the circ off???
you might want to add a spring check on the other side of this loop, - however there is such a think as sigle pipe convection, if the check is really stuck open, it will convect

cooler water is denser than warmer water and drops through it and displacing upward the warmer lighter water

Joe Mattiello

Taco IFC

The flow check will prevent flow from going backwards from the discharge flange. Looking at the arrow impossed on the pump casing, that will be the only direction of flow. This is important to remember for purging also. It's not uncommon to have ghost flow conditions when using flow checks integral type, or external type. These issues are typically system related because of a high pressure drop across that zone. John Siegenthaler wrote a nica article on primary secondary piping and some problems with ghost flow. For your reference I have attached it in a pdf format

Taco, Inc.
Joe Mattiello
Technical Service Technician
joemat@taco-hvac.com
401-942-8000 X 484
www.taco-hvac.com

Joe Mattiello

Taco IFC

The flow check will prevent flow from going backwards from the discharge flange. Looking at the arrow imposed on the pump casing that will be the only direction of flow. This is important to remember for purging also. It's not uncommon to have ghost flow conditions when using flow checks integral type, or external type. These issues are typically system related because of a high pressure drop across that zone. You may have to install another check valve at the other end of the loop. John Siegenthaler wrote a nice article on primary secondary piping and some problems with ghost flow. For your reference I have attached it in a pdf format

Taco, Inc.
Joe Mattiello
Technical Service Technician
joemat@taco-hvac.com
401-942-8000 X 484
www.taco-hvac.com

jerry scharf_2

Yep

Mark,

You got it right. When the pump isn't on, there should be no flow in either direction. The limits on this are the tradeoff between the head and flow losses of the flow check and it's ability to resist forward flow. With gravity heat migration, the pressures are very low, so it doesn't take much spring to prevent it.

jerry

Mark Mathys

Thanks for the answers everyone.

Meatball I have a wood boiler and gas boiler in a primary-secondary arrangement with pipe running out to the boiler in the garage. What I am wanting to do is use a strap-on aquastat to monitor the line temperature so when it starts to cool off the pump will circulate water out to the wood boiler. Everything works fine unless the wood boiler goes out and the gas kicks in. When this happens flow occurs and the pipes going outside conduct heat and get hot so I can't sense the line temperate. I think I will try to locate the aquastat a little further away where the pipe drop down about 4 feet before going outside. I was thinking the IFC pump would be an easy fix but I'm concerned about the loss of flow.

Mark