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Flow too slow ?

hunter29
hunter29 Member Posts: 128
edited January 13 in Radiant Heating

Hi Guys, finally have water flowing, However…

I have a four loop manifold with each loop apx 200 feet. 900 sf of basement concrete floor on top of two inch insulation.

I am using a Taco 007 feeding the manifold post mixing valve, the water seems to be circulating but the flow meters are not showing any flow, unless I am reading them wrong as there is water in them. I thought the red part on topped moved to show flow, the manual does not say.

I will reduce later but For now on start up the water is going in at 120* and returning at 65*. Been like this almost two hours, I was expecting to see some rise in return temperature by now.

Is the flow to slow or am I expecting to much to soon ? I was advised the Taco 007 was the pump to use..

Thoughts ?

TIA

«13

Comments

  • ethicalpaul
    ethicalpaul Member Posts: 7,083

    Why do you say the water seems to be circulating? Is there heat in the floor?

    120 returning at 65 sounds more like 120 not going anywhere and 65 just sitting there.

    Were the loops purged of air?

    NJ Steam Homeowner.
    Free NJ and remote steam advice: https://heatinghelp.com/find-a-contractor/detail/new-jersey-steam-help/
    See my sight glass boiler videos: https://bit.ly/3sZW1el

  • hunter29
    hunter29 Member Posts: 128
    edited January 13

    yes purged, it's moving through the heat exchanger so I know it's moving, but is it moving fast enough?

    This is first time start up, the floor is cold at 63*, I realize that is a lot of concrete to warm up. Just trying to determine if the pump is sufficient.
    Or any other issues..

    ETA .. I feel parts of the floor warming up and return temperature has increased about a degree or so ..

    ethicalpaul
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 16,997

    Probably just need to give it more time. Radiant takes time a big mass of concrete to heat up.

    LRCCBJ
  • hot_rod
    hot_rod Member Posts: 24,089

    those white plasyic knobs are also shut off vslves. Take them completely off to assure the ports are open

    Aldo the plastic flow meters turn, make sure they are CCW all the way

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • hunter29
    hunter29 Member Posts: 128

    yep there off and open.

  • LRCCBJ
    LRCCBJ Member Posts: 789

    Patience. Come back in 48 hours and address the issue again from the start. Nothing at two hours is meaningful.

  • hunter29
    hunter29 Member Posts: 128

    Right, I know it takes time, the floor is getting warmer, almost two degrees now.

    Just as long as I'm good with the 007, I just wasn't expecting to see all the heat taken out .

    The return is increasing just very slow.

  • hunter29
    hunter29 Member Posts: 128

    So I looked up how the flow meter works and there is not enough flow to give a reading.
    For what that's worth????

  • GroundUp
    GroundUp Member Posts: 2,243

    If you're not seeing flow, there is no flow. Unless it's piped backwards and you're pushing toward the return manifold (the one without the flowmeters), in which case, they can't read even if there is flow. If the system is properly piped and purged, you'd see flow on all loops immediately after powering up the circulator. Any amount of waiting is too long and will burn up a circ if there's no flow. Show us the final product please. 99% of the time, this is an airlock problem and the loops need to be purged of air. Not bled, actually purged- one at a time using an external pump.

    ethicalpaul
  • hunter29
    hunter29 Member Posts: 128

    Thanks for chiming in, I have addressed all these issues.

    Temperature increasing, I lowered supply to 100*, return is now up to 71* and rising.

  • GroundUp
    GroundUp Member Posts: 2,243

    So what was the culprit?

  • hunter29
    hunter29 Member Posts: 128
    edited January 14

    Nothing, I'm just a newbe starting up a new system for the very first time .

    I wish a had a stronger pump but this is working. I have a lot of cold concrete to warm up, that's going to happen slowly.

    I think I'll have good results by morning, I can reevaluate then.

    If I have to make a change I will.

    thanks

  • Kaos
    Kaos Member Posts: 410

    You should still see some flow on those gauges. A 007 is plenty to push through a plate HX, mix valve and 4 loops.

    ethicalpaul
  • hunter29
    hunter29 Member Posts: 128
    edited January 14

    It's pulling not pushing.
    What would be your guess?

    If fact it's pulling up to some degree as well. About three feet from the EX.

  • hunter29
    hunter29 Member Posts: 128
  • bjohnhy
    bjohnhy Member Posts: 81

    What do you estimate for temperature drop across that heat exchanger on the heat side? And gpm Flow?

    old_diy_guy
  • hunter29
    hunter29 Member Posts: 128

    I see some flow but not enough to pull down the gauge, unless the guage has issues, it sat on that wall for 12 years before being used.

    However I don't think it's a problem.

  • Kaos
    Kaos Member Posts: 410

    I think that 007 might be backwards.

  • hunter29
    hunter29 Member Posts: 128
    edited January 14

    It's going in the heat exchanger at 140* and coming out at 127*

    I don't know flow other then it's got a 006 moving it.

    For the floor it's coming out at 120* and I'm mixing that down to 100* and hopefully will drop it to 85* when things warm up.

    Right now the floor is still cold with areas of warm spots.

    But it's warmer each time I go down to check it out.

    BTW it's four loops of apx 200 feet, that's 800 for that pump.

  • hunter29
    hunter29 Member Posts: 128

    I pulled it to make sure nothing was wrong and there was no problem with the check valve.

    I did notice the direction of the impeller seemed backwards to me, but the pump can only turn one way.

    Can anyone tell me which way it is supposed to turn, I'll get a photo and tell you.

  • hunter29
    hunter29 Member Posts: 128
    edited January 14

    ok looking at this photo it's spinning clockwise.

    Otherwise the arrow is pointing towards the manifold.

  • Kaos
    Kaos Member Posts: 410
  • hunter29
    hunter29 Member Posts: 128

    That's the way have it, in another thread someone said 175 feet was a long run for a 007, I have 200 x 4.. ?? It's moving water, I can adjust the mix temperature quickly.

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 16,997

    Not a radiant expert by any means but I would have located the radiant circ to pump towards the resistance specifically the mixing valve.

    @hunter 4 loops of 200 but the pump only sees 1 200' loop as far as head goes

    GroundUp
  • Kaos
    Kaos Member Posts: 410
    edited January 14

    Take a picture of that 007 from the top to show the pump section castings.

    @EBEBRATT-Ed Unfortunatley a mix valve doesn't work backwards. The normal way these are always plumbed is with the pump pumping away from the mix valve. The pump could be move on the return side after the manifold but you have to watch pressure drop then as the intake might get too low and cause the pump to cavitate.

  • hunter29
    hunter29 Member Posts: 128
    bjohnhy
  • hunter29
    hunter29 Member Posts: 128
    edited January 14

    4 loops of 200 but the pump only sees 1 200' loop as far as head goes


    that's about ten gallons to push

    old_diy_guy
  • Kaos
    Kaos Member Posts: 410
    edited January 14

    Ok. Pump is good.

    So what is left, a check valve no working/backwards somewhere (ie does the 007 have an IFC?, check valves in the thermostatic valve?), air in the system, or manifold valves (either on supply or return) not open all the way.

    Unlikely, flow gauges are stuck. A quick check, close off the blue shutoff on the return manifold. Open the purge valve at the end of the return manifold. You should see some serious flow for a short burst.

  • hot_rod
    hot_rod Member Posts: 24,089

    yes you need to pump away from a 3 way mixing valve. Pumping into it will cause some flow to go across the valve, as that is the path of least resistance . Pumping from a 3 way assures there is no cross flow., it pulls from the H and C ports.

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    GGross
  • hunter29
    hunter29 Member Posts: 128
    edited January 14

    Check valve removed, you guys are telling me that pump is going to push ten gallons of water that fast?

    I myself don't know but I don't have any other place to look, I even cleaned the strainer shortly after start up to remove stuff.

    When I was filling and purging it I was using another pump, the water coming out the other end was not moving fast at all, if it was a 1/3 of a gallon a minute it was a lot.
    Vevor circulation pump you can get on amazon was what I used.

  • hunter29
    hunter29 Member Posts: 128

    I just had a thought, the screens on the mix valve, they could be clogged..

  • hunter29
    hunter29 Member Posts: 128
    edited January 14

    Well guess what, they were , it's flowing much better, not a ton , but the gauge is bouncing at 1/4 GPM. And the return temp jumped right away..

    I forgot about those screens.

    bjohnhy
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 16,997

    Some of those screens are very small mesh. probably smaller than they need to be.

    Maybe you should give the system a good flush.

  • hunter29
    hunter29 Member Posts: 128

    Its new, I kinda just did, it was likely just Flux. Your right very fine mesh. I removed them, have a strainer right above it

    Thanks everyone, if you guys still think 1/4 GPM x 4 is still low, I'll keep looking.

  • GroundUp
    GroundUp Member Posts: 2,243

    What model mixing valve is that? It all seems to be piped correctly but some mixing valves have a huge pressure drop (intended for domestic water) and don't fare well with radiant. The 007 is of no concern- it'll easily push twelve 200ft loops at .6 GPM if the fluid is mixed properly. That brings up something else- is this a glycol system or straight water? Also, in the photo, your far right loop is shut off. Are you positive that all the flowmeters have been cranked all the way out CCW as well as the white knobs?

  • hot_rod
    hot_rod Member Posts: 24,089

    I’d be tempted to pull the mesh out of the Y strainer also. Those mesh sizes are too small for hydronics. A dirt separator is a much better device for hydronic work.

    If strainers keep plugging you need to clean and flush the system better, fill it through a deionizer cartridge.

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • hunter29
    hunter29 Member Posts: 128

    I can see if it makes a difference, it's pretty big and coarse thou.. but worth a try, I think a better pump is the answer.

  • GroundUp
    GroundUp Member Posts: 2,243

    There is no "better pump". The one you have will easily serve a system 3-4x the size with twice as much flow.

    GGrossSuperTech
  • hunter29
    hunter29 Member Posts: 128

    That what do you suggest, others are telling me its not an appropriate pump, I am going to call Taco and see what they say. Everything else checks out, one last look at the strainer but I'm sure its clean.

  • GroundUp
    GroundUp Member Posts: 2,243

    "Others" like who? Certainly nobody with experience in the matter is telling you that. See my previous comment asking about the mixing valve, fluid, etc.