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Taco IFC heat bypassing

Mellow_2
Mellow_2 Member Posts: 204
The move of the flow chek from the suction to the supply of the circ was to keep the circ from seeing that psi drop. By having a restriction at the inlet of a circ we cause a drop in psi when circulating...... This can cause cavitation and burned out the windings...... The cheks in the supply of the circ works great. I have only had three fail on me, one was pinch at the O-ring (factory insalled wrong) and the second I think was the temp of the water and velocity of the water. I keep the temps away from 200 deg and set the speed better and it seems to have solved the problem. I have also had dirt in one but with the circs pumping away I do not see this as being a big problem. I had switched to grunfos when the cheks were in the return because they would keep failing and I noticed more noise from taco ifcs. hope this helps. mellow

Comments

  • Just heard today

    that there's been quite a few IFCs with heat migration issues - many more than the ol' circ and flowvalve combo we used since last year . Is anyone else experiencing this problem ? Is this the reason for the switch of the check placement ( from near the impeller to the discharge of the circ ) ? We recently started seeing the new style IFCs , but I don't know as of yet which version has the problems , or if it's both .

    Thanks in advance .
  • Joe Mattiello_2
    Joe Mattiello_2 Member Posts: 94
    IFC Check

    I welcome anyone with a similar problem to contact me, and I'll be happy to help with their problem. A common problem for ghost flow is piping issues. Sometimes check valves are required on both sides of the loop. System dynamics has a significant roll in gravity flow. Please see attached document extracted from John Siegenthaler’s technical corner article. This is just one example of ghost flow using a spring type check valve. Additionally, the check valve was moved from the suction to the discharge port, because of feed back from the field. Taco listened to what everyone wanted. Incidentally, Taco competitors also have the IFC in the same location, using the same type check valve. In fact the Taco has more spring tension requiring a higher pressure to crack the check.
    Joe Mattiello
    Technical Support Technician
    Tel. 401-942-8000 X 484
    Fax. 401-942-2360
    1160 Cranston St
    Cranston, RI 02920
    joemat@taco-hvac.com
  • DanHolohan
    DanHolohan Member, Moderator, Administrator Posts: 16,610
    Ron,

    are these on your new installations, or on service jobs?
    Retired and loving it.
  • I've had

    two 006 PNP's where the spring check has come out of its seat and jammed the impeller. I thought that perhaps the cartridge had burnt out, but when I took it apart, the spring check was all in pieces, jamming the impeller.

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  • DanHolohan
    DanHolohan Member, Moderator, Administrator Posts: 16,610
    Alan.,

    do you use a lot of these?
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  • B. Tice
    B. Tice Member Posts: 206
    Great..........

    Hey Alan, guess who just put in 2 006's with checks.......darn.Maybe I'll be lucky.

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  • Dan , these are all

    on new installs . We started using them on a daily basis about a year ago , probably a few hundred so far . The majority of the ones we used are the old style with the check opposite the impeller . We recently started seeing the new style with the check on the discharge . I'll ask Tuesday about more details . From what I know we've had more than a few customers call about zones overheating . Enough so that we are switching back to regular circs and flowvalves till we can find out what's going on .
  • Joe

    Thanks for the follow up . I understand that in some instances you need a check on supply and return , but very , very rarely do we have a problem with ghost flow using a regular circ and one flowvalve ( both Taco ) .

    Would you happen to know if the built in check has the same resistence to heat migration as a weight style flow check ? And does the internal check have more of a chance getting hung up with crud than a flow check ? Believe me when I say that I hope it's all system issues because the IFC has simplified my installs greatly .
  • DanHolohan
    DanHolohan Member, Moderator, Administrator Posts: 16,610
    Could it be

    debris in the system from the new install? Have you been able to examine inside the ones that are bypassing?
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  • DanHolohan
    DanHolohan Member, Moderator, Administrator Posts: 16,610
    What effect

    > The move of the flow chek from the suction to the

    > supply of the circ was to keep the circ from

    > seeing that psi drop. By having a restriction at

    > the inlet of a circ we cause a drop in psi when

    > circulating...... This can cause cavitation and

    > burned out the windings...... The cheks in the

    > supply of the circ works great. I have only had

    > three fail on me, one was pinch at the O-ring

    > (factory insalled wrong) and the second I think

    > was the temp of the water and velocity of the

    > water. I keep the temps away from 200 deg and set

    > the speed better and it seems to have solved the

    > problem. I have also had dirt in one but with

    > the circs pumping away I do not see this as being

    > a big problem. I had switched to grunfos when the

    > cheks were in the return because they would keep

    > failing and I noticed more noise from taco ifcs.

    > hope this helps. mellow



    did the temperature have on the check? Maximum fluid temperature for the circulator is supposed to be 2
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  • DanHolohan
    DanHolohan Member, Moderator, Administrator Posts: 16,610
    What effect

    do you think the temperature had on the check? Maximum fluid temperature for the circulator is supposed to be 240 F.
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  • John White
    John White Member Posts: 120
    IFC's

    I have been following this thread since Saturday, and will be all over it on Monday. Would appreciate direct calls on issues of this type, as a faster reaction would be likely. I am always interested in this sort of input.
    Dan, thanks for the good questions asked.

    Johnny White
  • hr
    hr Member Posts: 6,106
    www.neoperl.com

    > I have been following this thread since Saturday,

    > and will be all over it on Monday. Would

    > appreciate direct calls on issues of this type,

    > as a faster reaction would be likely. I am

    > always interested in this sort of input. Dan,

    > thanks for the good questions asked.

    >

    > Johnny

    > White





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  • hr
    hr Member Posts: 6,106
    Operating temperature of the check?

    I recall another contractor here having problems with checks exposed to high temperture on a solar applications.

    I stopped by the Neoperl booth at AHR in Chicago recently. As I remember they told me the white plastic checks they manufacture are listed to 200F.

    So I stopped by one of the pump booths (not Taco) and asked what their circs are rated to. 230F was the answer.

    Neoperl does make a black plastic check rated to a higher temperature, different type of plastic. As I recall that one was listed to 250F.

    I'd have the pump manufactures check the temperature spec on the checks they are installing. I'd rather they error on the high side :)

    hot rod

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  • I haven't been able

    to examine any of the recent ones . The service dept. usually handles these cases . But the circs do come back to my shop , so I'll take a look for them Tuesday .
  • John White
    John White Member Posts: 120
    Temp

    Hot Rod,
    Much appreciate the response, and I'll look at it in the morning. Can't believe this could be the issue.
    John White
  • John , are you

    a rep for Taco ?
  • DanHolohan
    DanHolohan Member, Moderator, Administrator Posts: 16,610
    Ron,

    John owns Taco.
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  • jwade55_3
    jwade55_3 Member Posts: 166


    Hows that for a manufacurer wanting to be in tune with what's happening in the trenches.

    J
  • Mellow_2
    Mellow_2 Member Posts: 204
    the effect

    not really sure.... Found the check had come apart inside the circ. Can the heat make the plastic weak and the cavitation make it vibrate apart? I have the circ running the buderus s-120 indirect tank with the g-115 boiler. The 2107 was working great when I left but I could not turn on the last of the two zones because of leaks in the bb installed by a "knucklehead". He had to repair some leaks in his bb piping and sayed he could blead the zone..... The next day, I had to go back on a no heat or hot water call..... The "KH" had changed every setting so I have very little info on how it broke but the parts were in the impeller of the circ that was trying to heat the indirect.
  • Always seems

    to happen when something new comes to market. Ghost flow was always a problem in the "old days" and it was a revelation when Grundfos and Taco came out with integral flow checks; seemed to solve the problem, but now they seem to have created a problem of their own.

    Hydronics in its infancy.
  • Doug Bird
    Doug Bird Member Posts: 22
    IFC Pumps

    Thanks to all for the comments on the IFC. I'd like to follow up John White Jr's earlier comments. There seems to be a little confusion about this great little time, space and cost saving idea Taco patented almost 10 years ago. Since I'm the Taco Product Manager for all the 00's, the buck stops here.

    First, the one and only reason we moved the IFC to the discharge was to assist installers with purging the pump when installed on the return line. "Pumping away" systems were never a problem. Cavitation was never a problem. We have tested these pumps for hundreds of hours to verify the design.
    Plus, we have shipped tens of thousands of these 006 with IFC in the suction to OEM fan coil manufacturers for hydro-air applications with virtually no problems.

    Secondly, from testing we performed, we found that the standard spring used in the Neoperl valve was not strong enough for our liking to resist gravity flow in taller buldings or ghost flow in P/S loops, so we made two key improvements to the standard design. We had Neoperl design a stronger spring just for Taco and we had them Ultra-Sonically weld the valve to prevent the parts from separating. No one else has these features. It costs more but it's the right thing to do.

    Regarding the "by pass" questions, here's a few things to consider. Since the IFC is a spring loaded plunger design, junk from the system can get lodged in the valve causing the plunger to stick open. I've had calls reporting valves stuck from solder chips, flux, wood chips....even a little frog taking his last swim! This can happen to any pump with the internal check. The good thing is it's easy to remove,clean and replace. Much easier than an in-line flow check.

    Also, in P/S systems, if the Primary pump has too much head and the secondary tees aren't spaced closely enough, you may get ghost flow thru some zones. That's why we increased the spring tension to prevent this.

    Hope this info helps. If you have any other questions on this or any other Taco product, please call me directly @ 401-942-8000. We're here to help.
  • Joe Mattiello_2
    Joe Mattiello_2 Member Posts: 94
    Bravo, Doug Bird!!

    Nicely done, I couldn’t of said it better myself.

    Joe Mattiello
    Technical Support Technician
    Tel. 401-942-8000 X 484
    Fax. 401-942-2360
    1160 Cranston St
    Cranston, RI 02920
    joemat@taco-hvac.com
  • DanHolohan
    DanHolohan Member, Moderator, Administrator Posts: 16,610
    Thanks, Doug.

    Can the check take 240-degrees F?
    Retired and loving it.
  • DanHolohan
    DanHolohan Member, Moderator, Administrator Posts: 16,610
    Bump

    > Can the check take 240-degrees F?



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  • DanHolohan
    DanHolohan Member, Moderator, Administrator Posts: 16,610
    And

    can higher temperatures lift the spring? Thanks for helping us understand, Doug.
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  • DanHolohan
    DanHolohan Member, Moderator, Administrator Posts: 16,610
    I did

    as you suggested, Doug, and gave a call to Taco earlier today. Got your voicemail. I look forward to hearing from you (we're still on Maui time). Or you can just let us know about the max temperature by posting here on the Wall. Mahalo!
    Retired and loving it.
  • Mark Hunt
    Mark Hunt Member Posts: 4,908
    Mr.Bird


    That was one of the BEST posts I have ever had the pleasure of reading on this forum.

    Taco is one of the few that respond OPENLY to concerns posted here.

    Thank you sir,

    and thank you Taco.

    Mark H

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  • DanHolohan
    DanHolohan Member, Moderator, Administrator Posts: 16,610
    I agree,

    but I'd love to know if the working temperature of the circulator is more than the working temperature of the internal check. I'm sure he'll get back to us (or me, and I'll pass it on) when he has the info.
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  • Mark Hunt
    Mark Hunt Member Posts: 4,908
    DAMMIT MAN!


    We're sleeping here!

    Now go do a Hula or something!

    HAHAHAA!

    Seriously.

    Taco is a stand-up company and I agree 100% with you Dan. Taco always answers.

    I am not sure why anyone needs an IFC to withstand 240 degrees though. Sorta' like asking a Pex manufacturer if we can use their product on steam systems. "Yah...you can...but you won't like it."

    Aloha!

    Mark H



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  • OK

    I'll buy the "debris in the line" argument because I've removed many ribbons of excess solder from our systems. Problem is that when I went to my supplier for replacement check valve/spring/o-ring assemblies, they drew a blank. Where can I get these?
  • DanHolohan
    DanHolohan Member, Moderator, Administrator Posts: 16,610
    Aloha!

    We hula while you're sleeping.

    I know that 240-degrees F is not a normal temperature for most hydronic systems, but that's what Taco is showing as the maximum rating for the IFC circulators, and from what Hot Rod reported from the check-valve manufacturer (see above), I thought it was worth talking about. My guests here are reporting breakdown and bypass problems, and I wonder if this has something to do with it. I also realize that there are many working successfully.

    Is the check rated for 200-degrees or 240-degrees?

    Would higher-than-normal water temperatures (like 220-degrees) affect the lifting of the check (as it might with a regular flow-control valve)?

    Fair questions, I think, and I look forward to hearing from the good folks at Taco. Thanks, Mark.
    Retired and loving it.
  • Doug Bird
    Doug Bird Member Posts: 22


    Dan, sorry I missed your call yesterday. I decided to post a response here rather than call you because by my calcs its still last night in Aloha land.

    Here's the deal on the temp rating of the IFC. The manufacturer of the valve rates the temp at 200F in their spec sheet. But we have done years of testing in our lab at temps of 230F+ with no failures. So we feel comfortable rating the IFC circs to the same temp as our standard 00 circs.

    In regard to the spring lifting at high temps, it depends on the system delta T and the height of the water column. In some cases, if the delta T is high enough and the building is 2 or 3 stories, the spring may not be able to resist gravity flow. We learned this early on and changed to a stronger spring.

    In line flow checks usually have a stronger resistance to gravity flow, however, its a double edged sword. They also have a higher pressure drop causing reduced flow from the circ. IFC pumps have a much higher performance than an equivalent circ/in-line flow check combo.
  • Doug Bird
    Doug Bird Member Posts: 22


    Alan, we offer replacement IFC kits for every model: Here are the RP kit numbers to ask for:
    006-047RP (models 003-009, including the new 00R Radiant)
    0010-025RP (models 0010,0011,0013,0014)
    0012-021RP (model 0012 only)

    Most likely, not all wholesalers will have them in stock, so please contact your local friendly Taco rep for help or if you hit a dead-end, call me directly. 401-942-8000. We'll need to make an effort to get these into local stocks. Thanks.
  • Doug

    Our service manager confirms the issue you brought up as the most likely cause - debris getting caught up in the check . Although we do drain the whole system down on every install , there is a good chance of casting shrapnel or solder or sealant or teflon hanging them up . When he was asked how many had to be serviced , there wasn't a hard number yet but he said " alot " . I will find out the real numbers as soon as I can and send you an email .

    I found only one return in the shop this morning . It was missing part of the check . The rest are back at the supply houses .

    Thank you Joe , John and Doug for the outstanding help . I've installed thousands of your circs , flowvalves , PRVs , air eliminators , zone controls - over 20 years and I know your company takes pride in manufacturing parts built to last .
  • Al Hanson_2
    Al Hanson_2 Member Posts: 4
    IFC's Vs Standard 00's


    Dougs comments are well supported by the return ratio that we see on IFC's in the field vs standard 00's. After the initial learning curve that is common in our word of mouth industry, the numbers show the rate of products returned is the same in New York State as it has been for the 00's over it's history.
    Our friends in the oil business have many 50 somethings like myself that have return side experience and the new location is again part of the evolution of this very dependable line. Revised thinking about purge location and return side replacements work fine.
    I started in a steam and hydronic only wholesaler in 1974 so I have sold all flavors of products over the years and have helped customers with these ghost problems over that time . In all but a few cases poor piping practices or pipe sizing are involved. This can be a challenge to even standard flow checks.
    Why are we always using piping that is too small?

    Good sizing practices and piping arraingments make everyone look good.

    Al Hanson
  • Al Hanson_2
    Al Hanson_2 Member Posts: 4
    Dan in Hawaii?


    Dan

    If you are in Maui Bob Muser and I did the Holiakala downhill on bikes. Don't miss it!

    Al Hanson
  • jwade55_3
    jwade55_3 Member Posts: 166


    Hey Al Hanson, how goes it in the great NY state?

    Jay
  • DanHolohan
    DanHolohan Member, Moderator, Administrator Posts: 16,610
    Yes,

    we're here for a month. We drive up the volcano and dodge the bikes coming down. :-)
    Retired and loving it.
  • Weezbo
    Weezbo Member Posts: 6,232
    Complacency ,isn't one of the Strong Suits of this community

    *~/:)

    solder, flux laden wood chips ,Christmas Tinsel would likely be a good place for the problems to have arisen.

    strainers are Good. I like strainers. :)
This discussion has been closed.