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Radiant heat questions

nickybotznickybotz Posts: 26Member
So I have radiant heat installed under my tile floor in a slab all in all working pretty nice. But for some reason I have a cold spot here and there . The returns on the manifold don't seem to be as hot as the feeds . I have access to a thermal imaging camera and will post the pics here I feel like if the water was circulating more or for a longer amount of time it would probably even out. There is a tekmar thermostat with floor sensor controlling this floor. In the last picture you can see the cold spot

Comments

  • EdTheHeaterManEdTheHeaterMan Posts: 367Member
    Thermal image appears to indicate that one of the loops is not getting as much flow as the one next to it. OR if your loop is too long the warmer area is the beginning of the loop and the cooler area is the end of the loop.

    What is your loop length? how long has the water been circulating when the thermal image picture was taken?
  • nickybotznickybotz Posts: 26Member
    All loops are less then 200' 1/2 pex, the heats been on all day well at least the thermostat I never checked though maybe the loop is closed at the manifold
  • nickybotznickybotz Posts: 26Member
    The first picture shows the manifold that feeds that floor
  • EdTheHeaterManEdTheHeaterMan Posts: 367Member
    edited January 17
    are you saying the pic number https://us.v-cdn.net/5021738/uploads/editor/mu/9zkdozly8daa.jpg is the same as thermal pic?

    if yes, then you have insufficient flow in the loop that is cooler. 200 ft is no problem. see if the manifolds have adjustable flow controls
  • EdTheHeaterManEdTheHeaterMan Posts: 367Member
    edited January 17
    can you tell by your experience with the install that the cooler area is the end of a loop that is working fine at the beginning? OR is the cooler area its own loop?
  • nickybotznickybotz Posts: 26Member
    It's at the beginning and the manifold does have an adjustable flow control
  • GordyGordy Posts: 9,482Member
    edited January 18
    What picture of the tubing layout correlates to the infrared picture?

    What is the insulation detail below if any?
  • nickybotznickybotz Posts: 26Member
    Picture number 7 it's an open basement not finished yet
  • nickybotznickybotz Posts: 26Member
    No insulation yet
  • GordyGordy Posts: 9,482Member
    You are positive those two loop returns are not where the cool spot is in the infrared? Sure appears to be that way.
  • nickybotznickybotz Posts: 26Member
    Wich two loop returns are you referring to
  • EdTheHeaterManEdTheHeaterMan Posts: 367Member
    edited January 18
    No insulation below... a big problem. the radiant heat is going down there. Long story... 6 years of oil burner service on a DIY radiant system ,and the basement was a sauna. Every year I told the customer to get the insulation finished. Also complained that the rooms above the uninsulated area were colder than the insulated areas As part of a divorce, the house projects needed to get finished. Insulation suddenly was completed and WOW the problem rooms heated properly, POOF, like magic!
  • EdTheHeaterManEdTheHeaterMan Posts: 367Member
    edited January 18
    So this pic shows one of the Flowmeters is different from the others? May just be the angle of the picture. You need to double-check that
  • hot_rodhot_rod Posts: 12,584Member
    turn all loops but the one with no flow, see if it works then. Could be an air bubble in that circuit

    Or lines crossed?

    Certainly you need insulation, but all loops should get about the same S&R temperatures after they run an hour or so. They should all show a temperature difference between S&R maybe not exactly the same, depending on the circuit load.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
  • GordyGordy Posts: 9,482Member
    Agree itโ€™s a flow issue.

    Is that ceramic plank style flooring, or hardwood in the IR pic
  • nickybotznickybotz Posts: 26Member
    It's ceramic tile , the gentleman who installed the boiler and all said I possibly need a bigger pump
  • nickybotznickybotz Posts: 26Member
    For some reason the return lines aren't getting hot
  • ZmanZman Posts: 5,533Member
    What model circ is installed on the problem loop(s). How many loops is that circ serving.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • nickybotznickybotz Posts: 26Member
    It's a 007 serving 3 different manifolds about 1000' on each 4 zone manifold
  • ZmanZman Posts: 5,533Member
    It looks like you have balancing valves and flow meters on the loops. What do they read?
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • nickybotznickybotz Posts: 26Member
    They say there's flow for sure, my educated guess would be air
  • GordyGordy Posts: 9,482Member
    What are the flow rates reading at each loop on the gauges?
  • ZmanZman Posts: 5,533Member
    nickybotz said:

    They say there's flow for sure, my educated guess would be air

    Air doesn't flow, it stops water from flowing.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • hot_rodhot_rod Posts: 12,584Member
    The white caps on then upper manifold will shut off that circuit, are they all open? Looks like two are tightened down and two are loosened? Remove them all and the circuit is wide open.

    Also on some manifold the clear plastic flow indicators on the bottom turn to adjust and balance flow, they should be backed all the way open. CCW if you face them them directly.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
  • GordyGordy Posts: 9,482Member
    edited January 19
    CCW=Counterclockwise ๐Ÿ˜‰
  • nickybotznickybotz Posts: 26Member
    They were all open I closed them to see if I can isolate the loop in question
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