Click here to Find a Contractor in your area.
Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.

Possible low flow in woodboiler radiant system

My system consists of a woodboiler with a Taco 001 on the supply pumping into my small mushroom building (still under construction). Upon entering the building the supply line splits, one line to the tempering valve which in turn leads into a Taco 009 and in-floor manifold (2 zones covering approx 1200ft2)

The other line heads to the sidearm connected to my 60 gallon Hot H2O. It is on this line I have 3 hydronic heaters teeing off each with Taco004. When I initially filled the system everything was running fine plenty of heat brought the place up to 20C with barely any insulation in the place.

We experienced some very mild temps so I shutoff the sytem for a few days. Now I start it up and despite the boiler temps being 170F the water entering the building is 50F. I find when I bleed the system on any component (manifold or hydronic heaters) the water flows fine and temps entering building shoot up as can be seen on my supply and return thermometers.

I have no plugs in the lines through the floor, none in the lines to the heaters. I've taken apart my thermostatic valve and cleaned the washer screens, though wasn't able to do all 3 as the contractor who put it together reamed pretty hard on the tempered union.

I suspect I have a plug in the sidearm tubes or my tempering valve is faulty? I can't understand why bleeding allows the water to flow fine, and why all of a sudden when temps drop below 32 does it decide "I'm done".

Any help is appreciated, I'm in quite a predicament here

Comments

  • farmerjohn
    farmerjohn Member Posts: 5
    meant to be a Taco 0011
  • farmerjohn
    farmerjohn Member Posts: 5
    Bumping thread with another comment/edit.

    I meant to say the circulator on the boiler is a 0011, the one on the manifold is a 007 and the ones on the hydronic heater lines are 004.

    since yesterday, I've bled every line, checked every circulator, checked the sidearm, checked to make sure each line was circulating water by pulling apart lines and running circulators. It seems the water is circulating until I close the system, suddenly circulation slows down.

    When I bleed the return manifold both thermometers adjust for the water temp that flows through. When I shut the bleed, my return thermometer drops quickly while my supply drops slowly.

    I take it the lack of comments either means I'm not explaining myself clearly or there are too many variables to hazard a guess.

    At this point, I'm willing to entertain any guesses as plumbing/heating folks don't want to come out in my neck of the woods. I've called 12 different plumbers in my area, only 1 has offered advice as opposed to only telling me I live too far out of the way.

  • Ironman
    Ironman Member Posts: 6,587
    Can you post some pics or a diagram of how it's piped?
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • Solid_Fuel_Man
    Solid_Fuel_Man Member Posts: 2,307
    Agreed.
    Serving Northern Maine HVAC & Controls. I burn wood, it smells good!
  • Zman
    Zman Member Posts: 7,001
    Absolutely need a sketch showing configuration, pipe sizes and distances. Also, is this an open unpressurized system? If so what are the elevation differences?
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • farmerjohn
    farmerjohn Member Posts: 5
    Pipe sizes are 1" both supply and return from boiler to manifolds. 1/2" in floor heating. The contractor I had install the infloor heating ran 1 zone incredibly larger than should ever be installed something like 1100ft, while 2nd zone is in the vacinity of 500. pipe to sidearm is 1"inch both supply and return. pipe to hydronic heaters x 3(Beacon Morris 8000BTU) is 1" x 3/4" enters 004 circulator the goes down to 1/2" all the way to return. On the return side 1'2" enters uponor thermal zone valve opens up to 3/4" then drains into 1" and back into 1" return.

    Elevation from boiler to inside building is approximately 9', then rises again to the hydronic heaters another 9 feet. This is an open unpressurized system. Unfortunately I won't be able to post any pics right now.

    I'm figuring it's an airlock somewhere. The reason I figure this is that the system had worked until I shut it down a week and a half ago, no problems. It had worked without the 004s circulating on the hydronic heater lines. the 2 pumps (0011, and 007) handled the whole system.
  • icy78
    icy78 Member Posts: 397
    If it worked without the 004s, but now that they are in it doesnt, are they in backwards?
  • Zman
    Zman Member Posts: 7,001
    Do you have 1,100 feet of tubing in 1 loop?
    How long is the run from the boiler to the house?
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • farmerjohn
    farmerjohn Member Posts: 5
    hey guys thanks for the replies, problem is solved, just a stubborn airlock. I drained the whole system above the boiler and refilled. Problem solved!

    But to finish up the questions, yes 1100 in one loop. much more than the recommended 700ft. the run to the mushroom building is 50ft as required by my insurance.

    Very relieved right now, started up a fire and the hydronic heaters are blowing to heat the place back up.
  • Solid_Fuel_Man
    Solid_Fuel_Man Member Posts: 2,307
    1100 feet of 1/2" PEX? Why is this story all too common :(

    Taylor
    Serving Northern Maine HVAC & Controls. I burn wood, it smells good!
  • hot_rod
    hot_rod Member Posts: 15,055
    Super-sized loops! That is a problem that will never go away

    There are probably some being installed as we speak :wink:
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    Solid_Fuel_Man