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Just had a call to a radiant job

Obviously the job isn't working correctly

Here is what's going on from what I see , I didn't go there yet?

The domestic water comes into the heating loop then goes thru the supply and then the return loop that way the water never becomes stagnant or get legionellosis disease. That's my new project, he did tell me that there is a 40 degree delta tee soo I am going to assume pump isn't giving enough gpm. I was thinking not enough baseboard, if that was the case would the delta tee be less?


  • RobGRobG Member Posts: 1,850
    edited March 2014
    Where to start?

    Run Forest Run, Run as fast as you can and never look back!!! In lieu of that, Sawzall surgery, cut it all out and start from scratch with a proper room by room heat loss. Add a gas cock while your at it. Isolate the domestic from the space heat. It looks like they jackhammered the floor to fit the expansion tank that is in the wrong place. It looks like the pex goes through a hole in the ceiling that was made with a hammer. And install a boiler, use the tankless water heater as a water heater. If this is an Internet lead I would RUN. 


  • icesailoricesailor Member Posts: 7,265

    They didn't even bother to clean the PVC exhaust pipe before they glued it together. Just because you use purple glue doesn't mean you don't have to clean the pipe.

    Do they require permits where that is?

    Anything as clucked up as that probably needs someone far smarter than any one here to fix it. The bad end to what started out as a good job. A few years ago, when this Green Revolution started, there was an earthy crunchy carpenter that added Green Heating systems to his offerings. He even bought a newer truck and put signs on it. "The Green Builder". I heard that his first two (and only) jobs went far south when he used all iron circulators with his copper and PEX. Last time I saw, there were no more Green Builder signs on his newer truck.

    If they want a price, you won't quote close to being high enough. The biggest health and safety mistake made in the last 20 years was when the  cheap homebuilders got hybrid water heaters approved. We knew better. They paid for the best. And the best is the worst.
  • SnowmeltSnowmelt Member Posts: 750
    How ?

    I like the run part I probably tell the costumer to try bigger pump.

    And get a room by room heat calc.

    Most likely get a indirect water heater too.

    Here is one of my questions, how does a company like radiant sell to states that you can't mix domestic water.

    Also just an FYI, I tend to a lot of trouble jobs where tankless is used for domestic and space heat.
  • GordyGordy Member Posts: 7,111
    edited March 2014
    Jack hammered floor

    Rob that's the drain for condensate.

    That's a 7/8 pex that they just love to sell.

    I agree with Rob you'll never be a hero for what it will cost to right this wrong.
  • IronmanIronman Member Posts: 3,403

    How does the DHW work? If I'm following the piping correctly, the cold comes through a BFP (imagine that), then through a PRV and into the cold port of the TMV. How will this induce circulation through the tankless when a faucet is opened?
    Bob Boan

    You can choose to do what you want, but you cannot choose the consequences.
  • SnowmeltSnowmelt Member Posts: 750
    Set up

    That what it appearances to be but if you look closely you will see the PRV then the BFP, if you look closely at the pressure reducer it is up in the quick fill position, then goes down about a foot and then tees in the heating loop, there's a check valve before the tee so it has no choice but to go up into the heating then back around into the tankless, always giving the loops fresh water..
  • GordyGordy Member Posts: 7,111
    Generic website

    Are you actually tying this to that website? Or is this a generic internet radiant company claim.
  • SnowmeltSnowmelt Member Posts: 750

    If you google radiant you will see this set up, that's what the plumber followed but he claims it's not getting warm in the house.

    I don't know what you mean.
  • heatpro02920heatpro02920 Member Posts: 991
    When I get these calls

    and go to a system that looks like that, unless it has worked for years and is just a repair of a part, say that was piped correctly and the circ went, sure Ill change a circ and leave, BUT if I go to a system that never worked properly and looks like that, I tell the customer that I will only work on it if we are ripping that out and putting it back the rite way..

    From that pic I would rip everything out and start over, mount the unit higher, make a board, pipe it correctly, ect... Is that a coupling in the vent pvc? why not use the rite size peice, and it looks like they went out of their way to make a mess of angles and crooked lines.... that is embarrassing ...
  • delta Tdelta T Member Posts: 428
    edited March 2014
    Gordy, I know why you were confused...

    I think the website Snowmelt is reffering to is not The latter links to a company out of Utah. never heard of this website until now. one of the designs they have on the website matches perfectly with what was installed in the system the OP is looking at. The website claims to be the DIY'ers best friend. Some of the photos of tubing installs made me laugh in a sad sort of pitiful way.

    To the OP I would RUN AWAY!! unless the customer is willing to actually spend the money to start from scratch and redo it correctly.
  • GordyGordy Member Posts: 7,111
    delta t

    thats what I thought. Radiant does not appear to be like the other.

    Talk carefully about specific companies they lurk here.
  • SnowmeltSnowmelt Member Posts: 750
    My fault it is

    Oops, anyways what would happen if I make it a closed loop system and just install an indirect water heater , not a storage tank just wanted you guys to know I know what I was talking about. But let's start from beginning , not enough baseboard or pump is undersized. Let me get a chance to go and look .
  • Tom41Tom41 Member Posts: 1
    edited March 2014

    Is it my imagination or should there be a valve at bottom of distribution loop where feed and return from heater are?
  • GordyGordy Member Posts: 7,111
    sawzall surgery

    In my opinion. You could have another thread runner talking about everything wrong with this setup.

    One thing it does not lack for is temp gauges.
  • SnowmeltSnowmelt Member Posts: 750

    I am not following what you mean?
  • SnowmeltSnowmelt Member Posts: 750
    Temp guuage

    Yep your right , can tell temp everywhere I actually think not enough baseboard with running square footage vs Lanier feet also primery pump is only getting 1.2 gpm that's not good.
  • Tom411Tom411 Member Posts: 1
    edited March 2014

    Snowmelt, I am looking at the supply from boiler to tee on distribution

    loop,what is to keep the water from going back over to the nearest tee with the power wire to boiler pump is

    that connects from distribution loop back to boiler which will cut down

    on supply to distribution loop for floor pex?

  • RobGRobG Member Posts: 1,850
    edited March 2014

    The funny thing is, for the price of the stainless alpha's and other wasteful piping, the person could have bought a combi designed for the the job and have a system that works. It is amazing how much people will spend trying to save a dollar. This guy probably had the low bidder (or he did it himself) do the work, and now he will probably pay the low bidder to try and fix it, again and again..... INSANE!!!

    I think MMM designed this project  :)

  • SnowmeltSnowmelt Member Posts: 750
    Not sure

    Not sure what your talking about, but it's a check valve there.

    Your right rob i am looking at same thing, he had another plumber do it.

    He called mye and said he wanted to keep the tankless for domestic water. I told him lets put a true combi unit separating the domestic from space heating with a navien combo unit.
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