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Radiant Heat Issue- Piping Issue

Recently had my garage convereted over to a living space for the family. Put in radiant heat system and connected to existing cold start williamson boiler. About 400 ft of 1/2 inch (room is 20X15ish) pex broken down into three seperate lines. The plumber has been back 5 separate times to bleed the system to no avail, he also re-piped to the boiler, adding an additional circulator as the one I had Taco 007 he says was not strong enough.

He bled the system each and every time, running the boiler and having the returns dump out into a sink the lines will run warm water after a few minutes, but when he closes up the system, the returns never tick higher then 70 degress no matter what. I have run the system for 12+ hours and returns remain 70 degrees and the feed lines are at around 150. The only area where the floor warms in a few feet away from the manifold (which is about 20ft from the boiler)

I believe there is a lock in the system. The plumber installed a circulator pump on the hot side of the mixing valve which I believe is in error. I''m pretty sure after reading these forums that the circulator should

be on the mix side and PULL the hot from the boiler and the cold from

the return and  then feed this mixed water out to the radiant. Also since the circulator is on the hot side it is pushing hot water through the cold side ( the entire cold inlet is as hot as the hot inlet). I believe this is creating a lock in the system. My thinking is the return water is competing against the circulator, and is having a hard time returning to the boiler. I tried to tell him this over and over again, but he wont listen, or just doesnt get it , which scares me!

Do you guys agree? I posted a pic.

Would you guys agree the the radiant circulator should be on the mix side and not the hot side. Also how would they pipe the return from the radiant, I know it should go back into the mixing valve via the cold outlet, but how would they pipe it back to the boiler without competing with the original Taco007 circulator is?

Thanks for the help and hope this makes sense.

Happy Veterans to those out there who served our country.


  • for sure

    For sure the installer did NOT follow the piping instruction from the manual. This job needs and repipe from a real hydronic heating company.. you are right about the pump location.
  • MikeinMass
    MikeinMass Member Posts: 9
    edited November 2013

    Thanks rjb. The first step would be to adjust that circulator for sure.

    My second headache is how do they pipe the return into the boiler and to the mixing valve correctly. I posted another pic. It seems the way the return is piped now is that the cool from the radiant flows to the mixing valve (which is correct) and also back to the boiler, but it's not making it's way into the boiler , because the exisiting circulator is pushing the return water from the other zones against the return from the radiant.  Is there a way around this?

    Also, the circulator in this pic, is on no matter what, so when the radiant is on, both circulators are running.

    Check out the pic, man talk about lame, looks my 2 yr grabbed the mouse.
  • be honest with you

    The installer knew nothing about this boiler and hydronic heating system of any kind... ur right about the quotation. First of all.. its required sawall surgery .. too many to list...pump for radiant in wrong place (as well positioned wrong), lack of manifold for proper flow, house pump in wrong place,, built in air scoop is disregarded, so many more .. wondering how this installer get the job?.. by the way, how's the pex tubings connected and the layout done before concrete was poured? Insulation under the pad and outer perimter of walls??
  • MikeinMass
    MikeinMass Member Posts: 9
    oh boy, getting a head ache!

    Attached a pic of the manifold and the pex layout.

    They just put the pex against the existing concrete slab, then did a mud job to level and put tile on top of it. 

    The company I hired to do the renovation contracted out the plumbing to this clown.

    I just don't know what the right way is to pipe this, and I'm guessing it's difficult to describe over the forum. The boiler was in place before they piped the radiant to it.

    And also, what is an air scoop?
  • oh man..

    Pictures not coming up, try reposting... .. air scoop built into that boiler serves its purpose, removing any air in the system while pump are running... its a highly recommended boiler by me and others that truely know boilers. So try reposting those pixs again.
  • MikeinMass
    MikeinMass Member Posts: 9

    Hopefully this worked this time
  • oh geezzz

    From the last 2 pixs... the pex fittings going to mainifold are way too restrictive for heating flow.. good for plumbing but not on hydronic heat... now the floor.. NO insulation at all?????? What did they use to hold down those tubing??? Electric emt clamps??? Better have some clause on warranty on that as its not approved holder for pex piping. Where are u located?
  • MikeinMass
    MikeinMass Member Posts: 9
    edited November 2013

    For the crappy manifold connections, are you refering to  area where I circled? I attached another pic to show how the pex is attached to the floor. and yes, no insulation! I live on Long Island NY
  • yep..

    Yep its those fittings... hope u didn't paid the job off... did you know the owner of this site is from Long Island and have many books wriiten based on his experience living with radiant heat?? What part of LI are u??
  • MikeinMass
    MikeinMass Member Posts: 9
    Didn't know that

    Thanks for letting me now. That could definitely come in handy. I live in Massapequa.Unfortunately did pay the job off, it was done in May! The contractor is stopping by in a half hour to investigate and is saying he is hiring another plumber to fix it, just want to be prepared this time around. And thanks again for all the time helping me.
  • make sure hes a

    Make sure he's a HYDRONIC expert! Not just a plumber because its pipes... and asked why there wasn't any insulation under the new slab .. its required.. post the answer please.
  • MikeinMass
    MikeinMass Member Posts: 9
    Where I stand

    Well his reason for not using insulation was that he hasn't used it in the past.He agrees that the plumber has no right in being a plumber, and he states that he will longer be using him. New HVAC professional is coming Tuesday, will keep you up. Have a nice saturday rjb---mike
  • you hire or

    You hire the new company or the contractor doing the hiring and eating the cost of his mistakes??
  • Weezbo
    Weezbo Member Posts: 6,232
    pull thru the mixer,

    "that the circulator should

    be on the mix side and PULL the hot from the boiler and the cold from

    the return and then feed this mixed water out to the radiant. Also since the circulator is on the hot side it is pushing hot water through the cold side ( the entire cold inlet is as hot as the hot inlet). I believe this is creating a lock in the system. My thinking is the return water is competing against the circulator, and is having a hard time returning to the boiler. I tried to tell him this over and over again, but he wont listen, or just doesnt get it , which scares me! "


    Mike seems rjb aced the exam . lol

    and you know what you read here could not possibly be any different today, that when you read that ,pull thru the mix part.


    the return line from the slab should T to the mix then T above the yellow handle of the boiler return like maybe a foot above . that will make it work if the three lines of the radiant have all the returns going to the return and all the suppies going to the mixed supply .


    though what i said will work . really , you have no gauges to let you know at a glance if what i just said is true . Gauges help.


    if you are looking for heat ,rather than the cure , you could teach the plumber something worth while . by asking him to cut in some gauges .


    once installed they would never have to be removed ...which would be a plus to the system. plus when he was doing that you could have him cut in a new "T" ten inches above the yellow handle that is above your return pump for the return line

    and install a check valve in the return line from the mix and floor to offer some resistance of the cooler water returning from the slab ( This will give the mixer a choice . and not allow water from the boiler to go to the mixer- from- the boiler return.)

    to now, connect to.


    with a gauge 2 1/2 " above the handle .a gauge 2 feet above the mixer mixed supply add the other gauge where the circ is located ,move the circ to the mixed riser beneath the mixed water gauge ,

    now seeing as how the boiler is down ....

    and you have a gauge telling you the temp of the supply to the mix ,another for the return to the boiler mixed UP to determine what the boiler is seeing, the supply temp of the boiler at the supply side of the mix ,the pump moved , you could turn it back on. bang . all kinds of heat will roll thru the floor .

    you will have heat , however , that is what we call a fixed mix or proportional fixed mix,

    it has no idea if it is winter or summer it just stays in what might be likened to a fixed supply temp usually fix mixes are ok for a garage or shop where heat is nice and all just that there is no one usually who complains ,

    like the car for example could care less if its 9 or 90 *F

    human beings though might not be comfortable with that. and prefer less bounce and more stability.

    really , while it would get you heat then and there , it is more honestly exactly what you do not want to keep happening meaning where you discover some destructive thing and then chase after a quick fix .

    this is why we burn daylight here , yes we can often address the immediate need and would like to help as many as we have stop in. however , if we can change your perspective and gain you some insight then we feel you can then make your plans or decisions at your own speed .

    where we say Turn That off , Now!

    as the first reply ,...thats different . or if we say

    get out of the house do not turn anything off or on don't look for the car keys Get outta there!

    head for someplace on foot away from the place ...then you really really should go with that .

    i just thought of something in this very moment while replying to you ,

    it involves gas appliances and motion detector lighting.... i had never even considered this thought ever.

    Often while helping others you help yourself.

    wow! huh? i have a lot of licenses i do not recall this in fuel gas ,nec or fire codes hmmm....

    sorry ,

    it is like that for me , now i will likely burn all kinds of daylight pondering and reading ... i have to head down the road, there is work to do ...

    you make the best decision you can and stay focused on the future .make a quick fix for now and cure it later , maybe with the same plumber who will now see with his own eyes that what you related to him was correct or with another contractor who understands what needs to be done.


    *~//: )
  • Weezbo
    Weezbo Member Posts: 6,232
    rjb , ..

    roll out to Mike things like finish trim nails and door jamb nails and screws and the likelihood of leaks , by finish carpenters ... where they are going to put the water that exudes from the pour and that sorta part of our thinking..

    i was off to the work site until...lol i found out the ceiling has no vapor barrier , the carpenters and electricians and the hrv guy are all over the place and no heat in the crawl space ..i feel like charlie brown lucy pulled the ball away again ..lol.

    i think procedure is often disregarded in the frenzy to get work done and the cost of fixing stuff that is right ruined by other trades does not have to be a part of the picture.

    do people hate using pipe supports on pex coming out of the slab? and roll swoopy 90's past Mike too. in place of the square 90's you mentioned.

    hydronics 101 on the cheap lol...
  • MikeinMass
    MikeinMass Member Posts: 9

    The contractor is hiring and eating the cost, atleast he is doing the right thing. He;s a nice guy, but unfortunately being nice does equate to a functioning radiant system!
  • MikeinMass
    MikeinMass Member Posts: 9

    This is really insightful weezbo and I appreciate the time you took to write that out.

    Too bad I can't buy you and rjb a beer over the net.

    But... I would buy you a twelve pack if you could sketch out what you are saying as I am a complete newbie when it comes to the "T' connections and gauges you are speaking about, and I do some much better with picture, but you have done much already to help me!
  • Weezbo
    Weezbo Member Posts: 6,232
    i am hard headed ..i went to the job anyway...

    not good.

    so, hmmm...

    i am not clever with paint and what not it even took me a long time to be able to post pics.

    Ok . so lets establish a place to start we can call this point A.

    the green 3 way mixers cold side, first takeoff from the horizontal, at the bottom of that 90 . would be easiest for me to go with.

    there is a "Drop of about 2'- and 1/2 " or so to a 90 that transitions from the vertical to the horizontal back into the room and away from the wall ,to another 90 laid on the "Flat" to a short 14" run to a t connecting a vertical drop about another 2 '- plus change to another vertical by horizontal transition 90 along a horizontal pipe of about 12 to 14 'run to another 90 on the flat headed at the boiler through a threaded "T" with a boiler drain along a section of pipe to a red handled valve .we can call that red handle valve B


    the first "T" we came upon when we made the drop from the 90 we called starting point A we can call C

    C drops to the red valve B which if we close it the boiler cannot see the water from the return of the radiant.it shuts off that er different looking cluster altogether.

    ok we will call the entire chunk of pipe and fittings 1. A

    my suggestion is get 1.A remove the drops and sweat the 90 at point A into a 2 1/8 pipe to the other 90that turns back into the room then run the pipe on the horizontal to the first "T" across to the return of the boiler , just a couple inches beneath the 1 1/4 90 off the zone valve return header. ( if that is one inch copper then forgive my eyesight and connect to it with a 1 X 3/4 T )... now on the Horizontal , of piece 1 .A , approximately where that piece of foam is on the pipe ahead of the green Taco circ ,..burn in a 3/4 " check against flow from the boiler return header . ok so now we have a pipe that goes from point A to the boiler return with a check valve in it and a T looking down from C.

    connect C to the radiant return pipe that being done the cold side will allow return water t go to C make a choice head to point A or head to boiler return and push open the check to do that so the water will be indicative of the radiant return ... at the moment we do not even have one of the gauges in place . we simply provided cooler water from the return a choice at C to go to the cool side of the mix or the return boiler header....or both...


    ok take the red handle valve out of the T you have and thread it into the red handle valve we turned off at B now to drain the boiler you have two valves to open.


    Now the chunk 1.A is about 1/2 " or so beneath the nut on the mixed water temp line.

    which means you can still get a wrench on the shiney chrome looking nut and another Grip on the valve itself. workable from a maintenance point of view.


    ok so now we can start another point we can call this one D D is that shiney nut on the mixer the pipe that heads down , transitions 90 from the vertical to the horizontal ,into the room 8 inches or so turns 90 up and is the supply To the radiant thru the mixer. on that pipe 2 feet up ..approximately in the picture you have which would be about 6 inches above the lowest edge of glass we can see in the window. we can call E right there install a paco temp gauge so you can see at a glance what the temp is going out to the emitter.



    now , this circulator you have looky beacoup heavy so it will need some means of support because we are going to move it away from its current location . which we can call F

    so we remove it and change it out in favor of a ball valve to a T with another gauge in it. to the Hot side of the Mixer.

    Ok . done deal there .... now lets look at that return water connection again . on the boiler header .... we have another gauge we want to install. this one will be just 2 and a half inches above that yellow handle above the Black return circ.

    that is going to show us the temp coming Back to the boiler . we want to know this info.

    after that is done and with the red valves closed and the gauges installed you ask the plumber if he would like to make a small discovery in his lifetime ...

    buh he will have to work for it because it cost time and aggravation for you to learn this stuff.

    let me know too , because this is an EYE opener.
  • Weezbo
    Weezbo Member Posts: 6,232
    3 new gauges.

    "Would you guys agree the the radiant circulator should be on the mix side and not the hot side. Also how would they pipe the return from the radiant, I know it should go back into the mixing valve via the cold outlet, but how would they pipe it back to the boiler without competing with the original Taco007 circulator is?"

    remember that we have not put the green circ back just yet.....

    and hopefully you had the forsight to shut off the water supply and electricity and drain down the boiler and loop ... or you are some very tired and frayed individuals about now : )))
  • Weezbo
    Weezbo Member Posts: 6,232
    what if i said ...

    now that you have it piped , that even without an additional properly sized circ , you could get that to circulate , if that can happen , then knowing what you know about water how much Bigger a circ should we put on the mix temp side for heat?

    what are our differential valves set at on the headers? if we want 36 gallon a m flow lol..

    how about we are happy with one gallon a min or less? lets not think this too hard and give our customer an Alpha ...set on auto. maybe it draws 14 watts or less.

    Mike , there are other ways to dial in your boiler room like rjb was saying and pieces you have could be rearranged and things you have could be traded out for more responsive items , however once you see that you can get heat then you can calm down a bit and find someone who knows how to take what you have and sort it out so it works even better . i think it is in your best interest to get that circ back and an alpha installed.

    under the gauge on the mix temp ...a sweat flange with a purge is a good thing .

    although the alpha should hang in there quite a while before you will need to do anything to it ....

    so i read back to where you are having someone else come by to commission it or whatever . not to worry, the gauges are still one powerful tool for a tech to read your system.,, do not be afraid st spend the coin now done deal one time because wages for folks like oil prices probably wont be going down any time soon. and if you can say , over the phone there is no heat in the return line , then that carries meaning to the tech , it means the transformer that controls the zones or the boiler circ is at fault you have a circuit breaker out is read off the alfa pump right now no light telling you how may wats or gpm , and no circulation ... trying to make heads and tails of things at two a m is rough especially when you could diagnose or tell them some information before they arrive and leave the shop....and things roll along like normal again as soon as the problem is corrected.
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